FAQ MATLAB Wiki FANDOM powered by Wikia. Basics. Back to top. What is a cell array Edit. A cell is a flexible type of variable that can hold any type of variable. A cell array is simply an array of those cells. Its somewhat confusing so lets make an analogy. A cell is like a bucket. You can throw anything you want into the bucket a string, an integer, a double, an array, a structure, even another cell array. Now lets say you have an array of buckets an array of cells or a Cell Array. Each bucket can contain something different, or they might all contain the same type of variable. Bucket 1 could contain a string, while bucket 2 could contain an image array of uint. XX/help/371361J-01/guid-56861f51-a133-4c0a-8bb4-e0a485378ac8-help-web.png' alt='Linear Program Polynomial Interpolation Matlab' title='Linear Program Polynomial Interpolation Matlab' />Or all buckets could contain strings of various lengths. Its totally flexible. String. ca2 my. Integer. Double. Array. ca4 rgb. Image. ca5 my. Structure. The braces should be read as contents of, so if you say ca4 rgb. Linear Program Polynomial Interpolation Matlab' title='Linear Program Polynomial Interpolation Matlab' />Key Features by Version. This information is also available as a PDF file. All Tables Expand All Collapse All The Feature was improved in the version. Im trying to do a scatter plot with a line of best fit in matlab, I can get a scatter plot using either scatterx1,x2 or scatterplotx1,x2 but the basic fitting. Image, you are saying that the content of cell 4 is the variable rgb. Image. Another way to use the cell is to refer to the cell itself, rather than the contents of it, and for that you use parentheses. The item it refers to must be a cell. For example ca1 is a cell, ca2 is a cell, and ca3 is a cell, even though those cells contain variables of arbitrary, and possibly different, types. To make something a cell, you enclose it in braces, like this. String. ca2 my. Integer. Double. Array. ca4 rgb. Image. ca5 my. Structure. This set of code is entirely equivalent to the first set of code. For the first line, its basically like saying Lets get a bucket a cell and put the string into it thats what my. String by itself is. Then lets take that bucket and make it bucket 1, replacing any bucket that was already there. In other words, take the cell my. String and make it be element 1 bucket 1 of the cell array called ca. It uses parentheses which means it refers to the whole single bucket the bucket plus the contents while the first set of code used braces which refers to only the contents of the bucket. So ca1 equals the cell my. String, while ca1 equals the string my. String because the braces said to get the contents of the cell. In other words, ca1 says dont give me the bucket with the string inside, just give me the string alone, without the bucket. Its just a slight difference a slightly different way of considering it. Saying. String  or saying. String. are equivalent for the most part. You can use either way and I dont really think one way or the other is really preferred. You can use whatever way is easier for you to think about it. Maybe one way will be more intuitive for you than the other way, but again, they are equivalent. Cell arrays are similar to structures, which you probably are more familiar with, in that both are containers that can hold variables of a variety of different types arrays, strings, scalars, even other structures or cells. The difference is that with structures you refer to the different members or fields by their name e. User. Settings. my. String, while with cells you refer to them by their index number e. Here is some demo code that may help explain cell arrays, and the type of classes you get when you use braces or parentheses. Installing Ati Drivers Opensuse here. Initialize a cell array with three different types of contents. First cell contains an int. Lets see whats in cell 1 and the difference between. The class of ca. 1cell is sn, classca. The class of ca. 1contents is snn, classca. Lets see whats in cell 2 and the difference between. The class of ca. 2cell is sn, classca. The class of ca. 2contents is snn, classca. Lets see whats in cell 3 and the difference between. The class of ca. 3cell is sn, classca. The class of ca. 3contents is snn, classca. Now lets see what gets displayed when we use the. Play Station 2 Copy Program more. Here is what celldisp returns n. One use of cell arrays is to hold lists of strings of different lengths. Since arrays are rectangular, you cant have an character array of strings unless each string was the same length or padded with blanks to be as long as the longest string. To get around that, you can use a cell array instead of a character array. Each cell in the cell array would hold a string of a different length they dont have to all be the same length like with a character array. For example. Short A little longer A really really long string. If you get strange error messages while working with cells or cell arrays, one easy thing to try is to change your braces into parentheses, or your parentheses into braces, and see if that eliminates the errors. Its also possible to mix indexing of the row and column of the cell array with the indexing of the contents of the single cell at that row and column of the cell array. For example, lets create a cell array of 2 rows and 3 columns, and in every cell of that lets put a 4 element integer array. Then well access the second element of the integer array at the cell in row 1, column 2 of the cell array. Create an empty cell array of 2 rows and 3 columns. Each element in the array is a single cell. Now, for each cell in the cell array. Number. Array randi9. Number. Array. An alternate way of specifying is given on the next line. Number. Array  Note changes in braces and parentheses. The integer array in row d, column d of the cell array d, d, d, dn. Number. Array1, random. Number. Array2, random. Number. Array3, random. Number. Array4. Print out the second element of the 4 element integer array. D array of cells. Value c1,22. The second element of the integer array in cell row d, column d is dn. Value. To visualize, imagine you had an array of buckets arranged in 2 rows and 3 columns this is our cell array, and in each bucket are 4 billiard balls arranged in a line. The above example goes to the bucket in the first row and second column, and reads off the number of the second billiard ball in that bucket. For further discussion see Loren Shures blog 1For more information, this link gives good examples about accessing cell data http www. Does MATLAB only calculate to 4 significant digitsEdit. It doesnt. Dont worry your number is not truncated. It uses full double precision floating point numbers to calculate everything. However, by default it only prints a few decimal places to the screen in the command window. You can change this, to print out more decimal places, using the command. Why does the transpose operator take the complex conjugate Edit. When performing linear algebra operations on complex matrices, it is almost always the complex conjugate transpose also called the Hermitian transpose that is needed see Gilbert Strangs linear algebra book for discussion page 2. The bare apostrophe is an operator that takes the complex conjugate transpose. The non conjugating transpose operator is a period followed by an apostrophe. Type help punct for more info. A   complex conjugate transpose. A.   transpose. How can I detect Na. N values in a matrix or vector Edit. By definition, Na. Graphics Driver Windows 7 there. N is not equal to any number, not even Na. N itself. Therefore there are two ways to detect Na. N values. Generate sample data. Na. N. Find Na. N values in two different ways. For speed purposes the use of isnan tends to be 2. Heres a test snippet if you want to see the comparison. A rand1. 00. 0 Random 1. ArandsizeA. Populate with Na.