3D bar graph of Z with data in X Y Z array

Hello,

I am having difficulty creating a 3D bar graph. I have the data in X Y Z array and need a 3d bar graph for Z.

Answer 1

[Konrad]

Hi,

provided that x and y are always positive integers, this may be a good start:

tab = readtable('XYZ_Data.txt');
zarray = zeros(max(tab.Y),max(tab.X)); % you could also use NaNs
lind = sub2ind(size(zarray),tab.Y,tab.X);
zarray(lind) = tab.Z;
bar3(zarray); % you may want to reverse the direction of your z-axis if z is always <0

Note that I assume that there is only 1 z-value per x- & y- coordinate.

Best, Konrad

[FNU Dhanraj]

Thanks Konrad for the help.

I was abbe to get the plot using the scriot you provided. Although there was one issue when running it. I get following error

Error: File: three_D_barPlot.m Line: 24 Column: 56

Invalid expression. When calling a function or indexing a variable, use parentheses. Otherwise, check for mismatched delimiters.

But when I run the commands one after another it works and I get the plot.

[Konrad]

Hi,

sounds like a syntax error. Please post your code.

[FNU Dhanraj]

Thanks Conrad. here is the code

tab = readtable('XYZ_Data.txt');

zarray = zeros(max(tab.Y),max(tab.X)); % you could also use NaNs

lind = sub2ind(size(zarray),tab.Y,tab.X);

zarray(lind) = tab.Z;

b= bar3(zarray);

for k = 1:length(b)

zdata = b(k).ZData;

b(k).CData = zdata;

b(k).FaceColor = 'interp';

end

I am able to generate the following 3d Bar graph. I want to increase the size of those bars. Is there any way to do that. When I am trying to increase the width they are getting overlapped on each other.

[Konrad]

I'm not quite sure what you mean by 'increase size'? Scale z-value?

As you noticed, you cannot increase the width because bars have a fixed position and there is no space left in between bars. Try playing around with x-,y-,z-limits or think about a different plot-type; e.g. 2d color-coded?

[FNU Dhanraj]

I want to increase the width of the Z bars like the following graph.

[Konrad]

The main difference in this figure is that there are fewer bars visible. Constrain your x- and y-limit and your bars will look similar.

set(gca,'XLim',[60.5 75.5],'YLim',[60.5 75.5])

Best, K

[FNU Dhanraj]

Thanks Konrad