Iterate over vector from result of a for loop

I have a vector capacity and I want to iterate over this vector in such a way that that in every iteration 480 is subtracted from the resulted vector for example capacity=[750 350 950 650 600 500 450 700 850 950]

loop 1=capacity-480
result=[270  -130   470   170   120    20 -30   220   370   470]
loop 2=result-480
result={-210  -610   -10  -310  -360  -460  -510  -260  -110   -10]

and so on..meanwhile save every result vector I tried different techniques but cant sort out the desired result e.g

for i=1:3
result(i)=capacity(i)-480
final=[result(i);result(i+1)]
end

but I cant understand how to do this.Any expert can help me out in this please?

Answer 1

[Stephen23]

This is MATLAB so there is no need to rely on low-level loops. For MATLAB versions R2016b and later:

capacity - 480*(1:5).'

or for older versions:

bsxfun(@minus,capacity,480*(1:5).')

[Christopher Wallace]

I like it. This is what I was imagining but couldn't think of.

[summyia qamar]

genius approach.thankyou.. I have matlab R2018a

Answer 2

[Aquatris]

Since the results will be a matrix, you should use 2 index;

capacity=[270  -130   470   170   120    20 -30   220   370   470];
result = capacity;
result2 = capacity;
for i=1:3
  result(i+1,:)=result(i,:)-480;
  result2(i+1,:)=capacity-i*480; % alternative way
end

The result and result2 look like this;

result =

         270        -130         470         170         120          20         -30         220         370         470
        -210        -610         -10        -310        -360        -460        -510        -260        -110         -10
        -690       -1090        -490        -790        -840        -940        -990        -740        -590        -490
       -1170       -1570        -970       -1270       -1320       -1420       -1470       -1220       -1070        -970

result2 =

         270        -130         470         170         120          20         -30         220         370         470
        -210        -610         -10        -310        -360        -460        -510        -260        -110         -10
        -690       -1090        -490        -790        -840        -940        -990        -740        -590        -490
       -1170       -1570        -970       -1270       -1320       -1420       -1470       -1220       -1070        -970

Here the first row of the result variable is the untouched data. The second row is when you subtract 480, the third row is when you subtract 480 twice from the capacity variable and so on.

Hope I was clear.

[summyia qamar]

Yes its very clear thankyou very much for the solution

Answer 3

[Christopher Wallace]

Here's one solution:

% Number of iterations
numberOfLoops = 10;
amountToSubtract = 480;

% Create an intial matrix to subtract from
capacityInit = [750   350   950   650   600   500   450   700   850   950];
capacity = repmat(capacityInit, numberOfLoops, 1);

% Iterate over the matrix and subtract the desired amount
final = capacity;
for i=1:numberOfLoops
    final(i,:) = final(i,:) - 480*i;
end

Answer 4

[Catherine Branter]

I have a similar sort of question if anyone is able to help please! trying to loop through a matrix - my model has no problem looping through the bandwidths "bw" but i get an error when looping through the priors

the input of prior works in the format when not using a for loop... but i want the model to run through 3 different types of prior probabilities

prior = [0.427,0.226,0.347];

the error i get is: Error using classreg.learning.classif.FullClassificationModel.processPrior (line 264)

Prior probabilities must be a vector of length 3.

when i print prior i get

priors =

0.3300 0.3300 0.3300

0.4270 0.2260 0.3470

0.2000 0.2000 0.6000

bandwidths = [0.2, 0.5, 1];

priors = [0.33 0.33 0.33; 0.427 0.226 0.347; 0.2 0.2 0.6];

global mymatrix

for f=1:length(bandwidths);

for l=1:length(priors);

bw= bandwidths(f);

p = priors(l)

Mdl = fitcnb(x_train_crossval,y_labels_train_crossval,'ClassNames', class_names,'PredictorNames',predictor_names,'Prior',p,'Width',bw);

[Aquatris]

your for loop is for the variable "priors" but previously you defined "prior" variable. So these two are two different variables. Make sure you are calling the right variable for the "i = 1:length(priors)" part