Counting the from when data changes to 0 then changes back to a number

This is my code:

%% Import data

numfiles = 54; % number of excel files mydata=cell(numfiles,1); % defining size of mydata d=dir('Trial*.csv');

for i=7:length(mydata) % loop to import mutliple excel files

try

mydata{i} = xlsread(d(i).name); % import files into mydata

catch

disp([d(i).name 'read failed'])

end

myfilename = sprintf('Trial%02d.csv', i); % define file name

mydata{i} = xlsread(myfilename); % import files into mydata

%% Perfrom Calculations

    %%Define variables 

      a= 9.81; % acceleration

      fps = 250; % frames per second

    %%Calculate Jump Height  

      no_of_zeros(i,1) = size(mydata{i,1},1) - nnz(mydata{i,1}(:,5)); %number of zeros

      no_of_frames = (no_of_zeros(i,1)/4); % number of frames 

      time = ((no_of_frames/fps)/2); % time up

      jumph(i,1)=((a*(time*time))/2); % jump height

Looking at the calculate jump height, it calculates correctly for the first 2 trials but then gives large over estimations for nealry all the other trails. It was a while ago I wrote this could someone clarify this line of code for me as this is where the trouble lies, I'm unsure with the ,1.

no_of_zeros(i,1) = size(mydata{i,1},1) - nnz(mydata{i,1}(:,5)); %number of zeros

[Azzi Abdelmalek]

What do you mean by changes to a number?

[Franchesca]

I have a vector of data which changes from numbers to a block of zeros then back to numbers, I need to count how many zeros are in the block however my code is not doing this correctly.

[Azzi Abdelmalek]

Franchesca, zeros are also numbers. Your question and your comment are different. Do you need to count the number of zeros or how many time they switch from zero to non zero?

[Franchesca]

Sorry, from the numbers to zeros so count the number of zeros from the point in the column where the first zero appears to where that block of zeros ends.

Answer 1

[Azzi Abdelmalek]

 a=[1 1 0 0 4 5 0  0 7 4 7 0 0 0 7]
idx=[ 1 a~=0 1]
ii=strfind(idx,[1 0])
jj=strfind(idx,[0 1])
out=jj-ii