Optimization in Indexing: Consolidate all switch/if statements into a smaller For loop??

I have a few For statements that sort large amount of data into smaller matricies (B1 to B92)

Question: is it possible to consolidate a bunch of these switch/case statements into smaller or more efficient indexing code that will 'change' variable names from B1 to B2... B92 when applicable instead of using a switch/case scenerio? I hope this makes sense. I am trying to reduce the amount of lines I have to edit on repetative code, so that in the future it will be easier to modify / add additional features.

if Progress == (Data(Update+k,1))
                       Sensor = Progress;           
                        switch Sensor                     
                            case 1                                    
                            B1  = [B1 ;Data(Update+k,:)];    
                            case 2
                            B2  = [B2 ;Data(Update+k,:)];
                            case 3
                            B3  = [B3 ;Data(Update+k,:)];
                            .
                            .
                            .
                            .
                            case 92
                            B92 = [B92 ;Data(Update+k,:)];
                        end
end

Answer 1

[Walter Roberson]

B = cell(92,1);

Then

B{Sensor}(end+1,:) = Data(Update+k,:);

No test needed, just the one statement.

If this is in a loop in which the entire update array is available then there are better ways available.

[Vadim Kachan]

Hi Walter,

Thank you, I will play around with that tomorrow and get back to you.

This is in a loop. I will have too look further into your example and see if I can make it work.

Right now the there are millions lines of data with each row being Bxx and the coloumns being the data. The data comes in a linear rythem such as B1, B2, B3 etc. and I have to pull that info out in a way that I can utilize it later on per each specific matrix or defintion ~B78(5,:) for example.

The switch case works but I would like to reduce having so many cases and just one if statement that loops till it builds the necessary matricies.

Big Thanks!

[Walter Roberson]

If the matrix already exists, then you should look at splitapply() using Data(:,1) as the grouping variable. For example @(v) {v} can be a function that gathers all of the entries into one place. Or you could

B = cell(92,1);
for K = 1 : 92
    mask = Data(:,1) == K;
    B{K} = Data(mask, :);
end

[Vadim Kachan]

Thats awesome. Thank you Walter!