matlab cellfun cell2mat

Is there a higher analog of "category with all same side inverses is a groupoid"? If you know your cell array is only going to contain ones and [] (which represent your zeroes), you can just use the function cellfun to get a logical index of the empty cells, then negate the index vector: If your cells could still contain zero values (not just []), you could replace the empty cells with 0 by first using the function cellfun to find an index for the empty cells: Thanks for contributing an answer to Stack Overflow! MathWorks ist der fhrende Entwickler von Software fr mathematische Berechnungen fr Ingenieure und Wissenschaftler. Why do some airports shuffle connecting passengers through security again. You may receive emails, depending on your. cell2mat does must all contain the same data type, and the resulting array is of Obviously I could proccess them as chars using the above and convert into uint8s at the end, but this limits significantly the size of the data I can process in RAM in one go. One row of the cell contains double values (such as 0.3421 0.5545 0.9199) and another row contains only int32 values (1 1 0). A = cell2mat (C) converts a cell array into an ordinary array. This syntax returns logical 0 ( false) for objects that are a subclass of classname. For By clicking Accept all cookies, you agree Stack Exchange can store cookies on your device and disclose information in accordance with our Cookie Policy. converts a multidimensional cell array, c, with contents of the same data type into a single matrix, m. The contents of c must be able to concatenate into a hyperrectangle. with a function handle, e.g. Site design / logo 2022 Stack Exchange Inc; user contributions licensed under CC BY-SA. Not the answer you're looking for? How do I put three reasons together in a sentence? Why is Matlab is not reading an empty cell while running an if statement? rev2022.12.11.43106. Can we keep alcoholic beverages indefinitely? tried the cell2mat function, all of the data ends up in one cell for some reason so it returns a [] matrix. Sie haben eine genderte Version dieses Beispiels. Site design / logo 2022 Stack Exchange Inc; user contributions licensed under CC BY-SA. To subscribe to this RSS feed, copy and paste this URL into your RSS reader. Cell arrays that contain the n inputs required for function func. Examples of frauds discovered because someone tried to mimic a random sequence. but if I need to convert back to uint8 via y=uint8(char(y)), the the above function that operates on uint8 only (without the need to expand to char or string) is the fastest. This MATLAB function applies the function func to the contents of each cell of cell array C, one cell at a time. When I want to transform the whole cell with cell2mat, I get a mismatch error. How could my characters be tricked into thinking they are on Mars? into an N-dimensional rectangle. The example shown below combines matrices in a 3-by-2 cell array into a single 60-by-50 matrix: The dimensionality (or number of dimensions) of m will match the highest dimensionality contained in the cell array. Syntax. : Now the input is a "read vector" and can be char or uint8. a cell array into an ordinary array. The important part here is that I did not have to specify and know the maximum length in the cell array - pad function figures it out nicely. Connect and share knowledge within a single location that is structured and easy to search. '14a' cellfun will apply your function to the contents of you cell array. Cell arrays that contain the n inputs required for function func. Convert Cell Array of Structures to Array, Run MATLAB Functions in Thread-Based Environment, Run MATLAB Functions with Distributed Arrays. accepts numeric, logical, or character data within cells of C, or We do not currently allow content pasted from ChatGPT on Stack Overflow; read our policy here. When I import data from a database, I receive it as a cell. Or convert all values to doubles before calling cell2mat using cellfun. What is the best way to replace an empty element in matrix with -1? PSE Advent Calendar 2022 (Day 11): The other side of Christmas. same number of columns, although they need not have the same number This syntax returns logical 0 ( false) for objects that are a subclass of classname. In the question you have mentioned a cell array. The corresponding function in Mathematica would be . Thread-Based Environment Run code in the background using MATLAB backgroundPool or accelerate code with Parallel Computing Toolbox ThreadPool. cell2mat. Any ideas? Irreducible representations of a product of two groups. Moreover, for each pair of neighboring cells, the dimensions of the cell's contents must match, excluding the dimension in which the cells are neighbors. Do non-Segwit nodes reject Segwit transactions with invalid signature? This function fully supports thread-based environments. A = cellfun ('isclass', C, classname) returns logical 1 ( true) for each element of C that matches the classname argument. Do you see any ways to parallelize it? The other method you mention is using cell2mat( ), but this puts the data in rows: Since matrices are stored in column-order in MATLAB, note that the first method above has better memory access patterns since the original row data is kept contiguous in memory in the final columns. That last option is what you see here. Add a new light switch in line with another switch? Why doesn't Stockfish announce when it solved a position as a book draw similar to how it announces a forced mate? Is there a function being able to transform the whole cell to a matrix in double? Convert cell array of matrices into single matrix. Based on For cell2mat Here is the fastest code that I currently use to achieve what I want: %Converts a read vector of chars or uint8s into an uint8 matrix padded, %with 0s based on the padded matrix string, %Locations of newline markers (ends of sequences), %Calculating lengths of sequences and shifting ends by 1 to remove eolns, %Max length of the sequence m and the number of sequences n, %Loading sequences into the new padded matrix. This will be the best for memory access purposes. Ready to optimize your JavaScript with Rust? I have an array of empty cells and ones that I want to convert to a logical array, where the empty cells are zeros. Each cell array must have the same dimensions. The main purpose of the matlab function cell2mat is to convert from so called cell arrays to "normal" matlab matrices, where cell arrays correspond roughly to "normal" arrays ( List) in Mathematica and normal matlab matrices correspond roughly to what Mathematica calls "packed arrays". A = cell2mat(C) converts Is it correct to say "The glue on the back of the sticker is dying down so I can not stick the sticker to the wall"? '36@' There are >50 rows. Display the first field of structure d(1). The elements of the cell array must all contain the same data type, and the resulting array is of that data type. Based on your location, we recommend that you select: . '@7@' The second method scatters the original row data throughout memory (the equivalent of doing a transpose copy), and I suspect that is why it runs so much slower. When would I give a checkpoint to my D&D party that they can return to if they die? Partition large arrays across the combined memory of your cluster using Parallel Computing Toolbox. Calculate with arrays that have more rows than fit in memory. Making statements based on opinion; back them up with references or personal experience. I need it for DNA sequences analysis. It matters if you want the row or column order. m = cell2mat(c) converts a multidimensional cell array, c, with contents of the same data type into a single matrix, m.The contents of c must be able to concatenate into a hyperrectangle. mat2cell | num2cell | cell | cell2table | cell2struct | struct2cell | table2cell | iscell. I wasn't aware of this.. To learn more, see our tips on writing great answers. cellfun then concatenates the outputs from func into the output array A, so that for the i th element of C, A (i) = func (C {i}). Link. When I use cell2mat, the empty cells are ignored, and I end up with a matrix of solely 1's, with no reference to the previous index they held. Feb 15, 2019 at 17:10. . It could even be multi-threaded if you really wanted to push the speed. Description. The rubber protection cover does not pass through the hole in the rim. MATLAB. Extracting data from struct within matlab table. Help us identify new roles for community members, Proposing a Community-Specific Closure Reason for non-English content. Other MathWorks country sites are not optimized for visits from your location. Counterexamples to differentiation under integral sign, revisited. How do I detect empty cells in a cell array? with an anonymous function. Otherwise, the results are undefined. Something can be done or not a fit? E.g., matrix_c=reshape([padded_c{:}],[],numel(c)). Accelerating the pace of engineering and science. The contents of C must support concatenation into an N-dimensional rectangle. - Replace empty cells with logical 0's before cell2mat in MATLAB. that data type. not accept objects or nested cells within C. This function fully supports tall arrays. missingCell = cellfun(@ismissing, T, 'UniformOutput',false); ismissing . Hi James, cool thanks for the remarks. 9. Ready to optimize your JavaScript with Rust? The contents of C must support concatenation Not the answer you're looking for? There are 3 ways to specify the function: as a char array (only a handfull of functions, but they are faster when called like this)\. A = cell2mat (C) converts a cell array into an ordinary array. For more For example given the cell array c: I can pad the cells with whatever character (say '@') using. cellfun works, but as you already mentioned cell2mat still fails, because of the string. The cell arrays are huge, could be holding hundreds of millions of uint8 vectors and even checking the maximum length with cellfun(@numel,c) is very costly. It seems to be that braking up, distribution and collection would eat out any benefits. It would be fairly trivial to write. The elements of the cell array must all contain the same data type, and the resulting array is of that data type. more information, see Run MATLAB Functions in Thread-Based Environment. Convert cell array to ordinary array of the underlying But I will go with your second suggestion, which I thought wouldn't be very neat, but it's pretty fast. I need it for DNA sequences analysis. The input argument func is a function handle to a function that takes one input argument and returns a . 0,7s in comparison to 47s with cellfun. I do not know beforehand which row is in32 and which is double, so it is not necessarily row 1 and 2, Or convert all values to doubles before calling. Are you open to creating a mex routine? Making statements based on opinion; back them up with references or personal experience. Help us identify new roles for community members, Proposing a Community-Specific Closure Reason for non-English content, Extract data from cell array and include index of cell for identification, Extracting data from struct within matlab table, i2c_arm bus initialization and device-tree overlay. A = cell2mat(C) converts a cell array into an ordinary array. We do not currently allow content pasted from ChatGPT on Stack Overflow; read our policy here. Delete elements within cells of array MATLAB, Concatenate subcells through one dimension of a cell array without using loops in MATLAB, Moving rows from a matrix to a cell array using matlab: Trouble indexing cells, Matlab remove empty cells from within cell array, How to combine matrix of different size in a cell array into a matrix in MATLAB, Return the cells in a cell array that don't contain all zeros in matlab, Change empty matrices to zero matrices of the same dimensions in matlab. PSE Advent Calendar 2022 (Day 11): The other side of Christmas. I thought of posting a C-Mex function, but as long as the type of the input is not clear, this would be a waster of time in 50% of the cases. Input cell array, in which all cells contain the same data type. your location, we recommend that you select: . Thanks! Choose a web site to get translated content where available and see local events and offers. Convert cell array of matrices into single matrix. A = cellfun ('isclass', C, classname) returns logical 1 ( true) for each element of C that matches the classname string. @mean. offers. Find the treasures in MATLAB Central and discover how the community can help you! Extract data from cell array and include index of cell for identification. Why does the USA not have a constitutional court? Connect and share knowledge within a single location that is structured and easy to search. and then convert it really fast to a matrix by: matrix_c=reshape([padded_c{:}],[],numel(c)); which is btw a way faster than cell2mat I could have used. Reload the page to see its updated state. Each cell array must have the same dimensions. Find centralized, trusted content and collaborate around the technologies you use most. What I want is the similarly performing function but on cellarrays of uint8s that occupy half of the space compared to chars. The structures must have the same fields. Convert numeric arrays in four cells of a cell array into one numeric array. This function fully supports distributed arrays. '@8@'. How do I arrange multiple quotations (each with multiple lines) vertically (with a line through the center) so that they're side-by-side? To learn more, see our tips on writing great answers. . sites are not optimized for visits from your location. By clicking Post Your Answer, you agree to our terms of service, privacy policy and cookie policy. Cell2mat for unequal lengths - MATLAB. If I use cell2mat on each row separately, I receive one matrix as double and one as int32. One would have to examine all the cell element headers to get the maximum length vector first (the equivalent of max(cellfun(@numel,c))), then create and fill the matrix. data type. Is it appropriate to ignore emails from a student asking obvious questions? cellfun cellfun for matlab cell2mat y=cell2mat(c) yx. Browse other questions tagged, Where developers & technologists share private knowledge with coworkers, Reach developers & technologists worldwide. Sie haben auf einen Link geklickt, der diesem MATLAB-Befehl entspricht: Fhren Sie den Befehl durch Eingabe in das MATLAB-Befehlsfenster aus. Description. Mchten Sie dieses Beispiel mit Ihren nderungen ffnen? {1N logical} . Find centralized, trusted content and collaborate around the technologies you use most. Choose a web site to get translated content where available and see local events and '25b' i2c_arm bus initialization and device-tree overlay. The contents of C must support concatenation into an N-dimensional rectangle. structures with the same field names and data types. Asking for help, clarification, or responding to other answers. On the characters the very fast solution is simply function pad. The elements of the cell array You can use cellfun to cast all data to doubles before using cell2mat: Thanks for contributing an answer to Stack Overflow! This would involve only one pass through the data and would not require any intermediate variables. Why is the federal judiciary of the United States divided into circuits? Japanese girlfriend visiting me in Canada - questions at border control? What properties should my fictional HEAT rounds have to punch through heavy armor and ERA? Combine the matrices in four cells of cell array C into the single matrix, M. By clicking Post Your Answer, you agree to our terms of service, privacy policy and cookie policy. Can virent/viret mean "green" in an adjectival sense? Why does the distance from light to subject affect exposure (inverse square law) while from subject to lens does not? A = cellfun (func,C) applies the function func to the contents of each cell of cell array C, one cell at a time. Otherwise, the results are undefined. of rows (see figure). Is this an at-all realistic configuration for a DHC-2 Beaver? You can also select a web site from the following list: Select the China site (in Chinese or English) for best site performance. Webbrowser untersttzen keine MATLAB-Befehle. Browse other questions tagged, Where developers & technologists share private knowledge with coworkers, Reach developers & technologists worldwide, Sorry, I now notice my description is incomplete. If your cells could still contain zero values (not just [] ), you could replace the empty cells with 0 by first using the function cellfun to find an index for the empty cells: emptyIndex = cellfun ('isempty', mycellarray); % Find indices of empty cells mycellarray (emptyIndex) = {0}; % Fill empty cells with 0 mylogicalarray = logical (cell2mat . I was thinking that perhaps I could stay on a single vector of uint8s from the start (without placing separate lines into cells) and then somehow inject uint8(0) in places after the end of shorter lines but I could not see a fast(er) way to do it other than copying across to another empty matrix of uint8s. Moreover, for each pair of neighboring cells, the dimensions of the cell's contents must match, excluding the . m = cell2mat(c) Description. EDIT: I do not know beforehand which row is int32 and which is double, so it is not necessarily row 1 and 2. How can I use a VPN to access a Russian website that is banned in the EU? Otherwise, the results are undefined. To save space I convert the sequences from the lines of char text to cellarray of uint8s and then I would need a fast cell2mat with padding. The elements of the cell array must all contain the same data type, and the resulting array is of that data type. 0. 1. I have a similar question I already found being asked but I need very fast solution that specifically converts cellarray of vriable length uint8 vectors into a matrix of uint8s with 0s padded to the end of shorter vectors. ismissing missing . The cell arrays are huge, could be holding hundreds of millions of uint8 vectors and even checking the maximum length with cellfun(@numel,c) is very costly. {1N logical} , cell2mat . Where does the idea of selling dragon parts come from? Asking for help, clarification, or responding to other answers. To subscribe to this RSS feed, copy and paste this URL into your RSS reader. You can also select a web site from the following list: Select the China site (in Chinese or English) for best site performance. What I want is the similarly performing function but on cellarrays of uint8s that occupy half of the space compared to chars. https://www.mathworks.com/matlabcentral/answers/1824393-fast-cell2mat-with-padding-or-numerical-equivalent-of-pad-function-that-works-very-fast-on-cellarray, https://www.mathworks.com/matlabcentral/answers/1824393-fast-cell2mat-with-padding-or-numerical-equivalent-of-pad-function-that-works-very-fast-on-cellarray#comment_2410708, https://www.mathworks.com/matlabcentral/answers/1824393-fast-cell2mat-with-padding-or-numerical-equivalent-of-pad-function-that-works-very-fast-on-cellarray#comment_2411128, https://www.mathworks.com/matlabcentral/answers/1824393-fast-cell2mat-with-padding-or-numerical-equivalent-of-pad-function-that-works-very-fast-on-cellarray#comment_2411793. The input is typically a text with lines of only a few characters arranged in sequences of up to 160 or so. For example, the contents of cells in the same column must have the Does integrating PDOS give total charge of a system? The input argument func is a function handle to a function that takes one input argument and returns a . Other MathWorks country Is that what you want? Is there a way to perform this operation without using loops? A = cellfun (func,C) applies the function func to the contents of each cell of cell array C, one cell at a time. How does legislative oversight work in Switzerland when there is technically no "opposition" in parliament? Accelerating the pace of engineering and science. How were sailing warships maneuvered in battle -- who coordinated the actions of all the sailors? . Convert structures in a cell array into one structure array. which results in [1,1,1,1], not [1,0,1,1,1]. - Cris Luengo. What happens if you score more than 99 points in volleyball? rev2022.12.11.43106. Why would Henry want to close the breach? cell2mat is not supported for cell arrays containing cell arrays or objects. Matlab cell2mat with different data types. cellfun then concatenates the outputs from func into the output array A, so that for the i th element of C, A (i) = func (C {i}). By clicking Accept all cookies, you agree Stack Exchange can store cookies on your device and disclose information in accordance with our Cookie Policy. information, see Run MATLAB Functions with Distributed Arrays (Parallel Computing Toolbox). Why does my stock Samsung Galaxy phone/tablet lack some features compared to other Samsung Galaxy models? So please post a small example of the input data and the wanted output. Your posted method starts with rows but ends up with the data in columns. more information, see Tall Arrays. 1 If he had met some scary fish, he would immediately return to the surface. m = cell2mat(c) MathWorks is the leading developer of mathematical computing software for engineers and scientists. timings on calling cellfun('isempty',mycellarray) vs cellfun(@isempty,mycellarray) for 367x367 sized cells (on a regular laptop): 'isempty': 0.002032 @isempty: 0.083621 Thx for the tip strange_dreams! 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