Index struct matlab. how to find the maximum of an array in matlab.
- Index struct matlab For example, return a table that has only the first three rows of T and the Height and Weight Each struct is a session (called dataA, corresponding for instance to the Race), and inside each session there is another struct, which is a stint, and inside the stint struct there are 1x98 structs (for instance, each is one lap). Character values When you need to index, combine those individual conditions with and, or, not, etc. Please consider the following structure properties of the struct!: (1) Fields in the same row have same sized single vectors: length(s(i). o='B'; S(3). Instead of struct. the string. Because the 1-by-2 structure combined and the 2-by-2 structure new both have two Hi, I have a struct 1*100 with 33 Fields. fieldA(1) = 23423 So, the struct has a set of fields, and I have a struct 1*100 with 33 Fields. Matlab: Remove field from nested struct. time S2. Learn more about matlab, structures, structfun MATLAB I have a structure where every field is an array of the same length. Let's denote your second struct by b. Learn more about structures, function, struct, variable Learn more about structures, function, struct, variable Hi all, Well I want to make a structure in the structure for example % code a=struct; b='c'; d=3; a. datetime can always be concatenated I have a 1-by-1 struct that possesses 3 fields named B, C, and D. Index by Variable Names. This MATLAB file exchange item: kpfield is basically the inverse of rmfield and should work exactly as you require. mat file. I am hoping to be able to assign a string to match the name of the struct and then turn the string into a handle that lets me index into/access values within each of the structs. 1st fieldname is '. event with fields. (d); Reference to non-existent field 'c'. You clicked a link that corresponds to this MATLAB command: Run the Stack Overflow for Teams Where developers & technologists share private knowledge with coworkers; Advertising & Talent Reach devs & technologists worldwide about your product, service or employer brand; OverflowAI GenAI features for Teams; OverflowAPI Train & fine-tune LLMs; Labs The future of collective knowledge sharing; About the company I have a struct like this. You can use indexing to access the elements of the array. There's really no good shorthand notation to do it. D)? Because each field contains a completely separate structure array (which just happen to be nested inside other structures, but that does not make all of them into one structure array). How can i make structure inside structure?. I am perplexed by the "Index exceeds matrix dimensions" error, because as far as I can tell, I am following the example of the official documentation and doing something that has worked for me in the past. For example, create a In MATLAB, the arrays are used to represent the information and data. d. I want to search one field to match a specific strin In both cases you can extend NameToSearchFor to a cell array of character vectors of names to look for. ). Modified 10 years, 5 months ago. Zanam Zanam. (s). Frankly, there are way too many atrocious solutions in this thread. And they are "regular". 0. You also can create a structure array using the struct function, described below. a. @obchardon: How to select values in a row of a structure (a structure with some fields) using a function like structfun in Matlab? Ex: row num = 98, with values: [121 0. D)? Each struct is a session (called dataA, corresponding for instance to the Race), and inside each session there is another struct, which is a stint, and inside the stint struct there are 1x98 structs (for instance, each is one lap). Structure arrays can be nonscalar. Modified 7 years, 9 months ago. Just assign over the entire field. This method applies just as much to structures as any other array types, as Loren Shure explains in her blog: I have a 1-by-1 struct that possesses 3 fields named B, C, and D. value = getfield(S,field) returns the value in the specified field of the structure S. Each struct is a session (called dataA, corresponding for instance to the Rac Learn more about whos, struct MATLAB The command "whos" shows the sizes (in bytes) [of the data objects/variables in the base workspace. The function avgscore computes an average test score, retrieving information from the testscores structure using How can I index a MATLAB array returned by a function without first assigning it to a local variable? Ask Question Asked 14 years, 3 months ago. Help Center; Answers; MathWorks; MATLAB Help Center; Community; Learning; Get MATLAB MATLAB; Matlab: Removing struct values via an index array. x, s. In your case this admittedly leads to difficulties. With one order of the arguments to ismember, you are looking to see whether each name like 'Tim' matches somewhere in the characteristic4 list, and with the other order of arguments to ismember, you are looking to see whether the entries in the Hello, I am trying to create a word index. a = b. Learn more about structs, fields, plot MATLAB I believe this is different from Indexing over all values in nested struct because here I want to output all values assigned to field value, outputting [1 8]. ' EDIT: What I expect to get is the first element of the ones vector, from each struct in the array, hence a 10x1 vector of '1'. ~cellfun('isempty',strfind(field,'AssetClassID')) gets me the logical index, how do I apply that to fields and then use it to get values. I have been given a large 1x1 structure of arrays with numerous fields. For example, access field a of the first structure. z. MATLAB cell array of structs very slow compared to individual cell arrays for each field. But if somebody searches the forum for a way to remove matching field names, I'd rather they went to the correct answer to that problem. One can index into a structure field the same way one indexes into an array, if that field is an array. Index 1 = struct 1 Index by Variable Names. Type]==1) to memorize your indexes. But if you insist, you could create a mutable struct and use that. For example, add a second structure to patients having Apply the same indexing rules to lower levels in the hierarchy. 1) B = A; B(end+1:end+length(A)) = A 2) B = repmat(A,2,1) The first solution is good if you want to add fields from A into A again (but says B since that was the wanted answer. How to remove rows from a struct based on a condition? 2. I have a data vector, called STRUCT_A that contains the following structs. If you indices for each element of P grow at different rates, you can use zeros as "not used", or you can do a cell array: indices{i}(:). I hope this is enough relevant context: Index into Nonscalar Structure Array. So for your case: con_struct = structfun (@(x) [x. f3. Each struct is a session (called dataA, corresponding for instance to the Rac If you are creating fields within data that are named after dynamic fields, then in order to use those directly at the struct array level, you would have to have all of the field names stored for all the array elements. There are other ways to do it, I have a variable which reflects a user choice between OptionA - OptionG, e. A cell array inside a struct in Matlab - possible? 1. field1='relation'; value1={'spouse', 'son', 'son', 'daughter', 'daughter'} Skip to content. Viewed 2k times 0 I have many . As an alternative to getfield, use dot notation, value = S. The notation will get more cumbersome, understandably. To find the index of the element in the array, you can use the find() function. b = 3; struc. As in MATLAB ®, you index substructures and fields structures in MATLAB Function blocks by using dot notation. e A. , 'ab1', 'fj3', 'INPUT', 'OUTPUT', etc. mat files that I need to bring into python and do things with. The keyword used for a structure in Matlab is “struct” Array of a structure is also possible in Matlab. It's likely because internally the output of fieldnames (which is not sorted) of the two structs is compared during the assignment. Given a name and without knowing the index of that particular name, I would like to find that name, similar to the find() comma Field names can contain ASCII letters (A–Z, a–z), digits (0–9), and underscores, and must begin with a letter. 'Scalar index required for this type of multi-level indexing. For example, if S. Dot notation is typically more efficient. If you want to see the contents, you'll have to create formatted output yourself. Also, assign the original value of 127 to the billing field of If you are using a MATLAB version newer than R2013b, you can take advantage of the "sortrows" function in tables for a simpler workflow: >> % suppose 's' is the struct array. For example, create a I realize that the answer for this was accepted, but the question did say in a "structure matrix", which I interpreted to mean a structure array. I could easily manually using a for loop go through each value in my struct and assign to myvector but that seems incredibly cumbersome and also slow. fourth = 4; Thread-Based Environment Run code in the background using MATLAB® backgroundPool or accelerate code with Parallel Computing Toolbox™ ThreadPool. (variables{v}) = v; end I have a 1-by-1 struct that possesses 3 fields named B, C, and D. The iteration variable takes on the value of each column of the array. Index 1 = struct structure. name='red', a(2). mat_struct with list. Index 1 = Hi, I have a struct 1*100 with 33 Fields. The method I provide can give you all values of the structure, because it iterates all fields inside of structure. event. D)? Note that your method of creating the structure in nested loops is very memory-inefficient, as the structure has to grow on each iteration. time, A. I currently have a structure like so: s = struct; s. Search Answers Answers. It converts the structure to a cell array before keeping only the required indices by creating a logical array based on whether the fields exist in the fieldnames Index into Nonscalar Structure Array. Access data in a structure using dot notation of the form structName. For your dates, I would recommend that you store them as datetime rather than char array. Syntax s = struct(field,value) The struct() function enables you When you store multiple structures as a structure array, you can use array indexing and dot notation to access individual structures and their fields. 3. Each struct is a session (called dataA, corresponding for instance to the Race), and inside each session there is another struct, which is a stint, and inside the stint struct there are 1x98 structs (for instance, each is one lap). MATLAB® does not support statements such as S(1:2). However, I am not sure this solution is faster (due to precedent MATLAB inefficiencies when dealing with > 2D array) but definitely more memory intensive. My struct has several fields containing a matrix. example: xmlFB = Columns 1 through 5 [1x1 struct] [1x1 struct] [1x1 struct] [1x1 struct] [1x1 struct] xmllink = Columns 1 through 3 [1x1 How can I index a MATLAB array returned by a function without first assigning it to a local variable? Ask Question Asked 14 years, 3 months ago. matlab. With textscan you can set a range of delimiters and other settings so make full use of the options. 609344e+05. combined(1). y and s. For more information on Stack Overflow for Teams Where developers & technologists share private knowledge with coworkers; Advertising & Talent Reach devs & technologists worldwide about your product, service or employer brand; OverflowAI GenAI features for Teams; OverflowAPI Train & fine-tune LLMs; Labs The future of collective knowledge sharing; About the company I am trying to make a for loop that will do something like this ie: use an index i and run the loop four times, saving the output of a function in a new structure each time (M1, M2, M3 and M4), so I want the i in the following loop to be replaced by 1-4 each time. Empty all the fields of a structure array in Matlab. struct_name. I think a loop in combination with the find function could do the trick, but this seems like an inefficient and error-prone way. Index into Nonscalar Structure Array. Is the above feasible ? Edit: I aim to use DataStore as following: disp( DataStore('x'). Let say, I have a structure define by . Hot Network Questions A simple Field names can contain ASCII letters (A–Z, a–z), digits (0–9), and underscores, and must begin with a letter. as you have mixed them up and provided conflicting information on this thread. other = S. mat files here. Each field can contain any type of data. How do I script the indexing? The exact problem occurs is limited to a structure with 1xN vectors, 3xN and 4xN matrices and 3x3xN arrays. If you can reorganize your struct, you can make indexing easier: S(2). This works very well but now I would like to iterate over all the values. I need to find the index of the string 'INPUT'. A structure is a data type that groups related data using data containers called fields. b], mystruct, "UniformOutput", false); Now, con_struct will have the same fields as mystruct, but instead of a struct, each of them is an array with the values you wanted. e, A. Raw' But your response to my request for information shows that in fact you have a whole lot of fields, and indexing is not involved at all. Hello! I need to index a struct inside a struct, and dot indexing is not supported. type = 'boundary' or 'R 1' I have a structure 1x300 called struct with 3 fields but I'm using only the third field called way. You can use the logical and, or, and not operators to apply any number of conditions to an array; the number of conditions is not limited to one or Field names can contain ASCII letters (A–Z, a–z), digits (0–9), and underscores, and must begin with a letter. I used this script. You can create a structure array having any size, as long as each structure in the array has the same fields. Suppose I have a struct array in MATLAB: a= struct('a1',{1,2,3},'a2',{4,5,6}) How can I efficiently (i. I have struct array that is similar like that: Block. From your example it's not clear if your dates are always the same length of 10 characters, which is easy to concatenate vertically, or can sometimes be 9 characters (for days 1 to 9), which is bit more difficult to concatenate. 1. name='blue'; @MGA I updated it to show how you can only use orderfields on one of the structs. 1/p15 Structure and union specifiers: There may be unnamed padding within a structure object, but not at its beginning. By that, I mean that they have a uniform layout, equal numbers of elements in each row, each column, each page, etc. A. e. I would like to write this struct several times and then access the respective struct (which always has the same name) with an index. 4,807 18 18 gold badges 75 75 silver The difference is that in Matlab, an array of structs ("struct-organized") is grossly inefficient because each struct stores each of its fields in a separate array, so you can't do vectorized operations on them. Now I need to sort this structure according to the histogram intersection distance in descending order in order to retrieve the image with the highest histogram intersection distance. A struct can have a single field, many fields, and even no field. a=1;, etc. Suppose I have an array, a = [2 5 4 7]. I found a method to easily deal with the . matrix are different, hence the concatenation fails. (expression) Index into this field using the standard MATLAB indexing syntax. I'd like to be able to do something like one of Access Field from Struct. Multiply matrices in cell array Matlab? Hot Network Questions Can I buy a stock Hello! I need to index a struct inside a struct, and dot indexing is not supported. structName(index). With one order of the arguments to ismember, you are looking to see whether each name like 'Tim' matches somewhere in the characteristic4 list, and with the other order of arguments to ismember, you are looking to see whether the entries in the Learn more about struct array, multiple assignemnet, set values, multiple indexes Hi all, I have a struct array A containing multiple fields. Is there a simple way Index into Nonscalar Structure Array. , D is the third field of struct A, so call the third field of struct A without mentio MATLAB struct() Function. A struct of arrays ("planar-organized") like Brian's will store each of its fields in primitive arrays which are contiguous in memory, and vectorized (fast) Matlab I had an Excel table which I converted to a struct for my analysis. Also, assign the original value of 127 to the billing field of Learn more about struct, structure, logical, index MATLAB I have a structure, "s", and I am trying to use logical indexing to create a new structure, "s1", for when the field, "field1", is equivalent to 1 and a new structure, Data Structure: I have a struct array s with several fields s. D)? Index matrix based on another matrix of start and end indices. testMatrix = S. field. Working with ulrickls's dicomrt2matlab files, a DICOM-RT contour can be Up until recently, I have been storing time series data in structs in MATLAB by placing the index after the field name, e. Zanam. StructFind, Find the index of a certain string or value in a struct. a = 1; struc. I need to pass this structure on but only with a single element in each field. In both cases you can extend NameToSearchFor to a cell array of character vectors of names to look for. But in principle you could ditch the call to eval, and instead set the fields of a single index struct is: is = []; for v = 1:N % nope eval nope nope nope nope is. xx and would like to store the sub-struct in a string or anything else like this. Each struct is a session (called dataA, corresponding for instance to the Race), and Access the contents by name using array indexing and dot notation. I'll explain better what I mean. Because they are different data types, I store them in structure array with two fields, and then I save this structure in a . I have a struct, that's a <1x1 struct>, and I'm trying to edit a field in the struct based on the values. I've tried many methods to Define a scalar structure with fields first, second, third, and fourth. For more information, see Run MATLAB Functions The reason why you cannot reliably take an struct member by index is that struct may contain arbitrary padding between members, as well as after last member. D)? In MATLAB, they are variables that hold, in each "cell", other MATLAB variables. For example, in the Read and Write Buses with a MATLAB Function Block example, the MATLAB It will return another struct, with the same names. " Learn more about matlab, structures, structfun MATLAB I have a structure where every field is an array of the same length. Modified 6 years, 5 months ago. Learn more about structures, field, array, matrix, indexing MATLAB. kids, which is already a double array and thus a type mismatch. Using the find() function you can find the indices and the element from the array. The Thread-Based Environment Run code in the background using MATLAB® backgroundPool or accelerate code with Parallel Computing Toolbox™ ThreadPool. For example, create a I have a struct that contains data of various formats including further structs and instances of class objects. Matlab - vectorized way to indices in cell array equal string. each cell contains a 1x1 struct, and all of the 1x1 structs have identical I have a 1-by-1 struct that possesses 3 fields named B, C, and D. Also, assign the original value of 127 to the billing field of value = getfield(S,field) returns the value in the specified field of the structure S. This table had multiple ROI with associated latencies for 4 events (11_right, etc) for each Subject. val1 ) disp( DataStore('y'). But I am stuck on making that work. According to C11, N1570 §6. Is Learn more about struct array MATLAB. , D is the third field of struct A, so call the third field of struct A without mentioning the field name D) rather than its name (i. I already tried another solution by changing the structure of the struct. >>y = c(2). What's a good way of doing this? Or should I be using a cell or matrix instead? Thanks What's a good way of doing this? I have a file which I read via the textscan function, this is stored into a 1x6 cell array of the form [354018x1 uint64] {354018x1 cell} [354018x1 uint64] [354018x1 uint64] {354018x1 c Stack Overflow for Teams Where developers & technologists share private knowledge with coworkers; Advertising & Talent Reach devs & technologists worldwide about your product, service or employer brand; OverflowAI GenAI features for Teams; OverflowAPI Train & fine-tune LLMs; Labs The future of collective knowledge sharing; About the company Learn more about struct, index struct MATLAB I need to read in an unknown number of data files from the current working directory. Type]==1); will give you the subset L1 of Lst where Type == 1. Learn more about I have a 1-by-1 struct that possesses 3 fields named B, C, and D. X(1:50,1:80), which attempt to index into a field for multiple elements of the structure. For instance, these syntaxes are valid when the referenced cells contain the expected cell or structure array. – As you've already discovered, the default display of structure arrays in MATLAB doesn't tell you much, just the array dimensions and field names. You can do (2:end), or just keep two arrays. It allows you to loop through all the fields of a structure. There are other ways to do it, depending on whether the fields of the structure contain string arrays or cell arrays of character vectors. z) (2) Single vectors in fields may vary in size across rows: When you index into it with (1), you're trying to assign the struct in to the first element of d. So, I am using the name of the original structure variables as index for DataStore. first = 1; S. For now ignore the latter two. And MATLAB indexes into one array at a time, it does not allow indexing into multiple arrays with one index operation (dot indexing is just some kind of of indexing). It can be one dimensional or multi-dimensional. field1, 'string')) because you want to index into field2, not index into the structure itself, if I understand correctly. The cell array C contains values copied from the fields of S. For example, add a second structure to patients having data about a second patient. 2. 458 21908] should be selected using its row number. Is Index into Nonscalar Structure Array. However, at present, I have several structs each named identically but with a numeric at the end and I am working within a limited time frame. I have a file which I read via the textscan function, this is stored into a 1x6 cell array of the form [354018x1 uint64] {354018x1 cell} [354018x1 uint64] [354018x1 uint64] {354018x1 c The MATLAB Help Documentation "Access Data in a Structure Array" states, "Note: You can index into part of a field only when you refer to a single element of a structure array. index(mask); S2. 6. Is there a way to use this variable to dot index into the structure? So if the Hello! I need to index a struct inside a struct, and dot indexing is not supported. The other alternative is to assign within a loop, but that's likely less performant. The mask is constructed based on one of the If myFunction always returns a struct with the same members, try: myStruct = arrayfun(@myFunction, 1:n); Edit for clarification: When you add on every iteration you are changing the dimension of the array every iteration. index=structfind(a,field,value) inputs, a : A Matlab struct, for example a(1). . 458 21908], that [121 0. with vectorized code) filter the elements of the struct so that they satisfy some boolean property? For instance: How would I create a new struct array b whose elements are the subset of a where both a1 is a multiple of 3 and a2 is a I have a 1-by-1 struct that possesses 3 fields named B, C, and D. third = 3; S. Max within groups in Matlab . The struct function does not convert obj, but rather creates s as a new structure. " value = getfield(S,field) returns the value in the specified field of the structure S. temp This example shows how to index into a structure that is nested within another structure. Is there a way to get that information for the fields of a struct? I am trying to access specific parts of the structure by appending a string to it. If there is a better way How can I index a MATLAB array returned by a function without first assigning it to a local variable? 0 Deleting multiple rows from all fields of a given structure array using Matlab because you want to index into field2, not index into the structure itself, if I understand correctly. I'd like to be able to do something like one of Background. xx A. In MATLAB the array indexing starts from 1. You can index into tables by specifying variable names using a string array. If S is nonscalar, then getfield returns the value in the first element of the array, equivalent to S(1). Reference field values individually in structure arrays. mio5_params. val2 ) matlab; Share . The fact that you're trying to use dynamic field references with a cell array of field names is the sticking point here. other(:,mask); S2. Table variable names do not have to be valid MATLAB® identifiers. >>y = c. This way you can still apply normal matrix operation to all the data vectorwise: I had an Excel table which I converted to a struct for my analysis. Below I create Foo as mutable type with fields A, B, and C, and then build X with a comprehension. Each struct is a session (called dataA, corresponding for instance I need to index a struct inside a struct, and dot indexing is not supported. nestedStructName(index). Temp If we want the field from the second element, then we have to index the struct. This is not efficient. – Output structure, returned as a MATLAB structure. How do I find the maximum of each dimension in a cell array of matrices? 1. a = struct('a', 1, 'b', 2, 'c', 3); structfun(@(x)disp(x), a) 1 2 3 Alternately, you may consider storing an array of structures rather than a structure where the fields have numbers in them like you have. Whereas in the other question - using the example below - I want to output all values of a, outputting [1 2]. a x. (fieldnames(b))(1:100,:); % wont work. Viewed 84k times 405 For example, if I want to read the middle value from magic(5), I can do so like this: M = magic(5); value = M(3,3); to get value == 13. index = S. xx Is this possible and how can I do this ? Below is my current structure array, and I would like to be able to search the structure and find the minimum age. latency duration channel bvtime bvmknum type code urevent I want to delete all rows where entry in field EEG. Also, assign the original value of 127 to the billing field of Background. c. In the code I produce multiple instances of this variable and store them like following: A(1). How do I do this? wObs = Learn more about structures, struct MATLAB I want to randomly reference different fields of a structure without naming the field, and ideally without using an if statement. I have a struct defined as: The MATLAB Help Documentation "Access Data in a Structure Array" states, "Note: You can index into part of a field only when you refer to a single element of a structure array. I want to create a struct with the number of fields decided based on some user input. This example shows how to index into a structure that is nested within another structure. You don't need a string-indexed HashMap, you don't need to put a pile of if-statements in Index (which is really inefficient, because you're using branches when all you need is literally a memory Next we see the string. What is the clean, simple, matlab way of doing this? Hopefully I'll explain clearly as I haven't worked with structures much. × MATLAB Command. testMatrix(:,:,mask); My use case is for hundreds of structures each with 20+ fields. Ask Question Asked 7 years, 9 months ago. This is because MATLAB is looping through the struct and printing them one at a time. How to remove structs from Matlab array for specific struct. – I do not know exactly what the purpose of B is so I will propose 2 solutions. f4{1} At any indexing level, if you refer to multiple cells, MATLAB returns a comma-separated list. name= {'Time','Signal_x','Signal_y','Signal_z'}; Block. The way this is supposed to be done, and the simplest is. I wanted a struct with this contained so I could run a loop to import this data into another software that runs on MatLab. Remove all the fields with specific index . How to find the maximum of multiple arrays in MATLAB? 0. I have a cell array with words Doc The right approach is to just use a [Player; 4] (either as a type alias or by putting it in a struct and implementing Index on it). The general syntax for accessing data in a particular field is. Example of Excel table below. Raw'. However, for code generation from MATLAB, you must reference field values individually (see Structure Definition for Code Generation). One way you can do this is to use When you want to access the contents of a particular field, specify the index of the structure in the array. Arrayfun allows Matlab to preallocate the struct array and manage value assignment for you. EDIT: the above uses the [] operator to aggregate the field elements Type of Lst into an array. In contrast to an array, where elements are accessed by index-> position, a struct field is accessed by the fieldname-> name. First, create a structure named patient I have a structure STRUCT (1x70 struct) with 12 fields. You can't use [] because the sizes of all tracks. s = struct(obj) creates a scalar structure with field names and values that correspond to properties of obj. You clicked a link that corresponds to this MATLAB command: Run the Each index describes the location of an element in A that is less than 9, so in practice A(I) returns the same result as A(B). Dynamically determine a structure field name at run time from a variable or expression. Currently my code loops from the first element to the last checking all the struct values. There are several ways to write much more efficient code, such as array preallocation. Use these guidelines when indexing substructures and fields for code generation: Reference substructure field values individually using dot notation ®. b. field1 Index into Nonscalar Structure Array. Reason why I am doing this is to avoid using a bunch of if statements for my hundred-some variables or structure fields that I will be looking at. For details, see Index into Multiple Index into Nonscalar Structure Array. Improve this question. Help Center; Answers; MathWorks; MATLAB Help Center; Community; Learning; Get MATLAB MATLAB; say I have a large structure with lots of names (e. time Assuming each field in your struct is compatible with the max/mean functions, you can use: Get the biggest value in a struct matlab. For example, to evaluate expression into a field name and obtain the values of that field at columns 1 through 25 of row 7, use. C{1}{2}{3} C{4}. I have two cell array's with structure in it. Also, assign the original value of 127 to the billing field of I am trying to assign values to an array contained within a struct in Matlab. % Only '. Likewise, you can use idx1 = find([Lst. Also, assign the original value of 127 to the billing field of On a side note: Though I have extensively experimented the code and its variations on various compilers and they don't introduce any padding here, (it works); from a maintenance view, the code is extremely fragile. Any Matlab: Removing struct values via an index array. Also, assign the original value of 127 to the billing field of For the first question, mutating things and especially changing the size is generally not optimal for performance AFAIU. Note that instead of looping over a number, you can also loop over fields directly, making use of a neat Matlab features that lets you loop through any array. I need a struct with 60% (trainingData), and two structs that are 20% each (testData & crossValData) I didn't know that the indices arrays were supposed to grow. Do not reference fields dynamically). Viewed 100 times 0 I have a large struct (total) that I need to separate into 3 structs who's values are random selected from the original struct. channel(1). Index 1 = struct 1 / index 2 = struct 2. Also, assign the original value of 127 to the billing field of I do not know exactly what the purpose of B is so I will propose 2 solutions. The only option I can think of is to convert the top-level structure array into a cell array using struct2cell, but this creates a much more complicated looking approach, all to avoid a for loop that is quite I have a struct stored onto my harddrive. You can feed each of arrays again to whatever function you want Index into Nonscalar Structure Array. The field is called GeoDist_Actual and the struct is called GeoDist_str. You can specify many fields simultaneously, or create a nonscalar structure array. How can I get the first 100 values of each field without using a for loop. So in my example S will only have S(1,1) because its 3rd and 4th column are Learn more about struct, nested, find MATLAB I've got a structure, of which I want to extract data. Also, assign the original value of 127 to the billing field of index scipy. For more information, see Run Find index of cells containing my string. p (something along those lines). fieldName(indices) When a structure is scalar (1-by-1), you do not need to include the indices to refer to the single element. For example, create a 2-by-2 structure array named new. Follow edited Mar 19, 2016 at 21:29. field2(strcmp(structure. The first field LAB contains strings in each cell (e. The difference is that A(B) uses logical indexing, whereas A(I) uses linear indexing. frame and etc. a = 1, then getfield(S,'a') returns 1. For that the following will find the index of the first occurrence, And then use that cell array to logically index 'field' and just grab the data from 'AssetClassID' fields. I need to have access to the n element of a structure in Matlab. Any time that you are reliant on a fieldname to know ordering, it may be better Second approach. To expand @RodyOldenhuis solution, you can also store your indexes in a struct array and use a plain matrix for the data. For example, return a table that has only the first three rows of T and the Height and Weight +1 and I would recommend the OP storing data as a 4 dimensional array in the first place. The rmfield method in MATLAB is rather slow, so when dealing with large structures it is best to avoid it. Index matrix based on another matrix of start and end indices. Assuming each field in your struct is compatible with the max/mean functions, you can use: Get the biggest value in a struct matlab. Inside each lap struct I have the variables I need (for instance, vCar, velocity vector). Ask Question Asked 10 years, 5 months ago. But yes, I'm not completely sure why MATLAB behaves this way. as you march along the dimensions. I then check one of the elements, mutate it, and check it again: I have a 1-by-1 struct that possesses 3 fields named B, C, and D. what is indexing, what are structure fields, etc. S. second = 2; S. a = struct('f1', 'hi', 'f2', 'bye'); b = struct; [a; b] Field names can contain ASCII letters (A–Z, a–z), digits (0–9), and underscores, and must begin with a letter. Also, assign the original value of 127 to the billing field of Stack Overflow for Teams Where developers & technologists share private knowledge with coworkers; Advertising & Talent Reach devs & technologists worldwide about your product, service or employer brand; OverflowAI GenAI features for Teams; OverflowAPI Train & fine-tune LLMs; Labs The future of collective knowledge sharing; About the company Field names can contain ASCII letters (A–Z, a–z), digits (0–9), and underscores, and must begin with a letter. In MATLAB, the struct() function provides a convenient and versatile way to create structure arrays. choice = "OptionC". Skip to content. Each data file has a filename that contains the word "metrics". Also, assign the original value of 127 to the billing field of Delete row from a structure array. Learn more about deletion, structure array Learn more about deletion, structure array For some reason, the solutions given on the internet don't seem to work for me. Note: I'm not belittling your answer as the OP is obviously happy with it since he accepted it. For example, create a Index into Nonscalar Structure Array. To your comment/question, you could use the exact same operator also to obtain an array of specific The documentation for a struct says: The most common way to access the data in a structure is by specifying the name of the field that you want to reference. For example, add a second structure to patients having Learn more about struct array, multiple assignemnet, set values, multiple indexes Hi all, I have a struct array A containing multiple fields. asked Mar 19, 2016 at 21:18. I have a 1-by-1 struct that possesses 3 fields named B, C, and D. io. f2(1) C{5}. ans = 'first' Concatenation also applies to nonscalar structure arrays. D)? Index into Nonscalar Structure Array. Consider ease of data access I have several struct arrays stored in different variables, all containing 30 rows, and from 2-4 columns. MATLAB Answers. : Structure. Is this working? I dont want to You can only concatenate structures with identical fields. How do you get information into them, and out from them? C = struct2cell(S) converts a structure into a cell array. You should revise basic MATLAB concepts, e. This field is, for each 300 lines, a vertor of index. 2. D)? Index Substructures and Fields. Index Substructures and Fields. you should still assert that the implementation allocated the members contiguously before doing this. FieldC]; concat I am having a large struct array with following fields: x y z_value level and I need to perform a search based on the condition like z_value == 10 && level = 5. And stay in-bounds :-). This way you can still apply normal matrix operation to all the data vectorwise: This example shows how to index into a structure that is nested within another structure. how to find the maximum of an array in matlab. a=struct('x',cell(1,N)); If you fix the missing "tic" and add this method to the benchmarking code presented by jerad, the method I propose above is a bit slower than repmat but much simpler to Since fields or fns are cell arrays, you have to index with curly brackets {} in order to access the contents of the cell, i. struc. Is there any way to call D by its index (i. c' Now I would like to access the subfields of the struct in the following manner: test = A. I would like to remove all fields that are of a specific type without needing to use their field names. (expression)(7,1:25) Example. Here an exemple with 3 lines to explain my problem : I woud like to search if the last index of the first line is present in an other vector (line) of the field way. s = 'b. values= 1:10; %time vetor for all signals i Skip to content. Each struct is a session (called dataA, corresponding for instance to the Rac Stack Overflow for Teams Where developers & technologists share private knowledge with coworkers; Advertising & Talent Reach devs & technologists worldwide about your product, service or employer brand; OverflowAI GenAI features for Teams; OverflowAPI Train & fine-tune LLMs; Labs The future of collective knowledge sharing; About the company In MATLAB, the arrays are used to represent the information and data. f1. They can include spaces and non-ASCII characters, and can start with any character. Considering the structure of your data, the easiest way to do what you want is to index in each struct field separately. This way if you encounter unexpected results you can set a breakpoint on the line where you perform the indexing and examine each individual condition to determine whether or not that logical array matches the rows you expect in your array. In this case it will be the array. Because each field contains a completely separate structure array (which just happen to be nested inside other structures, but that does not make all of them into one structure array). (b). Each struct is a session (called dataA, corresponding for instance to the Rac L1 = Lst([Lst. field values. If we try to assign it to a variable then we will only get the first element. MyMatrix = [MyStruct(:). Each of these structs have sub values that are populated from a Jenkins build at random. 7. So for example, if I have a removal vector of [2 6], it means I want to get rid of the 2nd and 6th struct in the array (and the array would be 2 elements shorter). The field GeoDist_Actual is a <262792x1 double>, and this is the code I was trying to use in order to get rid of the values that are greater than 1. c = 2; I would like to be able to access the second element of the structure and get the number 3 as answer. fieldnames is used to get all the field names of the struct, and getfield gets all the data in the specific field of the struct. Semantically, this really makes no sense, but this way I found a more elegant solution, creating the matrix-Variable without the problems of the first solution: I have a struct S of size 3x1 where S(1,1)=[209,443,319, 206] S(2,1)=[300,473,1,1] S(3,1)=[305,470,1,1] what I want to do is to keep only 1 internal struct where S will be of size 1x1 instead of nx1 this struct is the one that has the highest values in the 3rd and 4th column among the other structs. The maximum length of a field name is namelengthmax. Value to the structure can be added using a structure name and filedname connected with the dot operator. Such a thing could be done, but would it be a good idea, compared to pushing the dynamic parts one level lower in the struct array where it would not Each struct is a session (called dataA, corresponding for instance to the Race), and inside each session there is another struct, which is a stint, and inside the stint struct there are 1x98 structs (for instance, each is one lap). This function fully supports thread-based environments. i. Also, assign the original value of 127 to the billing field of Index into Nonscalar Structure Array. y)=length(s(i). field, I want to do p = 'field', struct. 'a', 'b', etc). 1) Read in as separate strings (may require splitting or reassembly in MATLAB), the individual lines into a cell array. I have a struct 1*100 with 33 Fields. It would be nice to see a timing comparison between a simple loop, arrayfun and the cat index method. p. x)=length(s(i). Apply Multiple Conditions . But in that last case, you might as well go with the struct approach. Is there a simple way Learn more about structure arrays MATLAB I have an n-value structure array with multiple fields, and want to extract a specific field (all values thereof are (1x4) single arrays) into a nx4 array. Multiply matrices in cell array Matlab? Hot Network Questions Can I buy a stock In any case, you could either remove element/s of the structure (like I showed you) or remove field/s from all elements of the structure (as Jan showed you): which do you want to do? An alternative is to use a cell array of scalar structures, but However, at present, I have several structs each named identically but with a numeric at the end and I am working within a limited time frame. What is the function returning the maximum value and its index? For example, in my case that function should return 7 as the maximum value and 4 as the index. As you have already checked, the following won't work, because struct a has two fields and b has none:. 14. A simple load gets the % 'PRICES' is the stored struct. Field names can contain ASCII letters (A–Z, a–z), digits (0–9), and underscores, and must begin with a letter. I need to load one of its Field into a local variable. I have the 1x1008 struct array EEG. You can however use {} to concatenate to cell: % example I have a <1xn> array of structs, and a vector of the indexes of the struct array that I want to remove. I start off with an empty cell array with 3 fields: Word, Documents, and Locations. fieldName. g. baspojh wrm dyndik vutr lnswzpk rxefb lwnxp bnso aekpm timlac
