String Class for Confusion Matrix

Hi, my code is like below :

predictors = [apple apple watermelon watermelon orange orange];
validationPredictions = [apple apple apple apple orange apple];
confuseMatrix = confusionmat(predictors, validationPredictions);

Where :

• predictors = Class names (string data type) of data training.
• validationPredictions = Class names (string data type) as a result of classification.

What i know is, confusionmat need for integer value type for both of True Class and Predict Class.

I got error for running my code above, it seems the data must a integer but my classes is string. How to solve this?

If possible, i need a Confusion Matrix like this (taken from Classification Learner App Toolbox) :

[Tom Lane]

If I run this right before your code:

      apple = {'apple'}; watermelon = {'watermelon'}; orange = {'orange'};

then I get a matrix result with no error. How did you define these variables? What release of MATLAB are you using?

[Angga Lisdiyanto]

My variable is a matrix, not a cell. Now is ok with cell type, thanks.

I am using Matlab R2015b.

But how to give a string label?

It is very confusing if we read CM without X or Y tick class/variables.

Answer 1

[Angga Lisdiyanto]

Okay, i got a solution. The solution is by using confMatPlot function from Matlab's File Exchange .