MATLAB: How to get the length of flame front

measurement

Hi everyone, does anyone know how to code for measuring the length of flame front as seen in the picture above?
My lecturer suggest to me use everyone point (x,y) of the respective temperature to calculate the distance, i'm very new to coding, i appreaciate any help
Here is my csv attachments and matlab code for this 2D surf contour plot
filename = '40um.csv';
Data = csvread(filename,6,0); %read csv data
X_Data = Data(:,2); 
Y_Data = Data(:,1);
T_Data = Data(:,6);
T_Data(T_Data>400)=300; %more than 400K equal to 300
[x,~,xi]=unique(X_Data*1e3/2); %convert m to mm
[y,~,yi]=unique(Y_Data*1e3/2); %option: divide by 2 to use for validations
subs=[xi yi];%use the indices instead of values as coordinates
[X,Y]=ndgrid(x,y);%generate the grid surf() expects
val=T_Data;
M=accumarray(subs,val,[],[],NaN);%fill missing with NaN
surf(X,Y,M); 
surf(-X,Y,M); %Reflection along y-axis
colormap jet
view(0,90),xlabel("x/R (mm)"+newline),ylabel("y/R (mm)"+newline)
xlim([-2 2]); ylim([-0.5 3.4]); c=colorbar; 
title(c,"Temperature",'FontSize',9,'FontWeight','bold'); title('0\circ');
shading interp

Best Answer

You have to find first value in each column
ii = zeros(columns,1)
jj = 1:columns;
for j = 1:columns
    ii(j) = find(M(:,j)>200,1,'last');
end
L = hypot(diff(jj),diff(ii));
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