# empty logical matrix matlab

Replace empty cells with logical 0's before cell2mat in MATLAB. The second expression involves an elementwise logical operator ( | ). 0 ⋮ Vote. It works great when the null space exists, and I get an 8X1 vector for "u". Hello, I have a program that evaluates mode shapes using the null space of an 8X8 matrix, "K". A simpler solution very specific to your problem is to convert the cell directly into a matrix: cleanedA = cell2mat(a); It converts to a normal matrix, and while doing this it removes the empty cells. Why? How do I detect empty cells in a cell array? let's take line 1 and line 2 in which at 2 points column 2 and column 3 the logical matrix has both 1's in row 1 and row 2 this information should be stored in 1D cell array. Use ClassName.empty to create a 0-by-0 array of the ClassName class. However, for some values of "K" there is no null space, so for that "u" I get "Empty matrix: 8-by-0" and need to use a different method. 0. While many MATLAB users will be familiar with the use of [ ] as a way of removing a row or column of a matrix (e.g., A(:,1) = []), or omitting an argument in a function call (e.g., max(A,[],2)), fewer will be aware that [ ] is just one in a whole family of empty matrices.Indeed [ ] is the 0-by-0 empty matrix What is the best way to replace an empty element in matrix with -1? Matlab's logical data type does not appear to have a constructor other than the logical function itself. Syntax. MATLAB: How to use an empty matrix in a logical if statement [] empty matrix if isempty logical operator MATLAB. tf = isempty(A) Description. In this case, the first part of the expression, 1, is true, so the second part, after the elementwise or, is never evaluated. Follow 1.275 views (last 30 days) ahmad Al sarairah on 14 Oct 2019. I want to create a 1D cell array based upon above matrix which should tell in which two sentences same words appear with value = 1 i.e. That being said, you can effectively typecast a double array as a logical array very easily, where all nonzero values become logic 1 and all zeros logic 0: This function is useful for creating empty arrays of data types that do not have a special syntax for creating empty arrays, such as [] for double arrays. How to create empty matrix in matlab? MATLAB. @BenVoigt: I understand that, I was just providing what I thought were relevant documentation links :) If you want more bizarre behavior, try: A(:,min(1,end)) vs. f = @min; A(:,f(1,end)).The parser interprets end statement incorrectly here, thinking that f is an array to be indexed, even though it is a function handle.. Test if array is empty. For example, if str is a string containing zero characters, then str == "" returns logical 1 (true).For more information on testing empty strings, see Test for Empty Strings and Missing Values.For information on string comparison, see Compare Text. Use ClassName.empty(m,0) to create an m-by-0 array of the ClassName class. Vote. 0 × 0 empty logical array However I need a Single Value and not logical array. MATLAB Function Reference : isempty. Then, of course, you can reconvert it to a cell array with the following command: a = mat2cell(cleanedA, [1 1], [1 1]) Commented: Image Analyst on 15 Oct 2019 I need to create an empty matrix, and I have 100 images . An empty array has at least one dimension of size zero, for example, 0-by-0 or 0-by-5. I know the command to remove the empty cell is a(1) = [], but I can't seem to get MATLAB to automatically detect which cells are empty. It works great when the null space exists, and I get an 8X1 vector for "u". Empty Arrays with Logical Operators. 2. I have a program that evaluates mode shapes using the null space of an 8X8 matrix, "K". So the fact that an empty result returns false never comes into play here. To determine whether a string array has empty strings (string elements with zero characters), use the == operator. tf = isempty(A) returns logical true (1) if A is an empty array and logical false (0) otherwise. Note that I cannot use any and all functions to reduce Logical Arrays to Single Value, beacuse I faced with other problems when "A" array is not yet empty! 0.