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