Check If Some Fields Exist On Mat File

Firstrowb 2 firstrowb.

Check if some fields exist on mat file.

If our file path exists our code will return the python boolean value true. It does not work for directories. Check for existence of mat file in search path. Exampleobject b 1 firstrowb.

Just came over an interesting problem. File does not exist. To determine if a field exists at any level in a nested structure create a new function that examines all levels of the structure. Access specific parts of a variable in a mat file using the mat file object.

If isfile filename file exists. Save the function as a matlab file named myisfield m. The isfile function searches for files only on the specified path or in the current folder. For very large files the best practice is to read and write as much data into memory as possible at a time.

Same applies for the seamount image or any other images that come along with matlab toolboxes. If i run exist mandrill file i get false back which i normally would interpret as the mat file doesn t exist in the matlab search path. For example if name matches both a file with a m extension and a p code file then exist returns 6 identifying it as a p code file. If name matches both a folder and a matlab function exist returns 7 identifying it as a folder.

For i 1 length myfiles clear myvar. Open the matlab editor and paste the following function into it. Isfolder and isfile search for files or folders only on the specified path or in the current folder which can lead to clearer and faster results. Firstrowb exampleobject b 1.

The isfile method only works for files. For example you can save data to a subset of a variable in a mat file or read a subset of a variable into the matlab workspace. If name matches both a variable and a p code file exists returns 1 identifying it as a variable. Display the value of myvar.

Myfiles dir mat. Exist searches for files and folders on the search path which can lead to unexpected results. However imgdata load mandrill works perfectly fine. To check the existence of a file or folder you also can use the isfolder or isfile functions.

For r2017a and previous releases use the exist function. Update the values in the first row of variable b in example mat using the values stored in firstrowb. If there is no existing file and therefore no existing file path our code will return false. If you use isfile to check whether a directory exists the method will return false here s an example of isfile being used to check if a.

First create the mat file object m. Load myfiles i name myvar if exist myvar var disp myvar num2str myvar.