first time use Histogram, need help

need help

[the cyclist]

You say you need help, but you don't really say what help you need.

• Describe what you are trying to do, in more detail.
• Share any code you have written yourself.
• What input data do you have? Can you share the data here (by uploading a MAT file with the data)?

[Xiao yang]

input data from Density - Frequency table, which I photo from my text book, need help how for to plot Histograh.

Answer 1

[Adam Danz]

In MATLAB, I recommend using the histogram function.

histogram('Categories',Categories,'BinCounts',counts)

x = reshape([0.29:0.01:0.4], 2, []);
xlabels = compose('%.2f-%.2f', x.');
y = [30 75 32 9 3 1];

figure
histogram('Categories',categorical(xlabels), 'BinCounts', y, 'FaceColor', 'red')
ylabel('Frequency')
xlabel('Density')

Note that the x-values are not continuous. For example, there are no data between x=0.30 and x=0.31. This is why the ranges are plotted as categories.

Answer 2

[Star Strider]

The histogram has already been created.

Use the bar function to plot it —

x = reshape([0.29:0.01:0.4], 2, []);
y = [30 75 32 9 3 1];

figure
hb = bar(mean(x), y, 'hist');
hb.FaceColor = 'r'; 
Ax = gca;
Ax.XTick = mean(x);
Ax.XTickLabel = compose('%.2f-%.2f', x.');
pos = Ax.Position;
xl = xlim;
yl = ylim;
xapf = @(x,pos,xl) pos(3)*(x-min(xl))/diff(xl)+pos(1);                % 'x' Annotation Position Function
yapf = @(y,pos,yl) pos(4)*(y-min(yl))/diff(yl)+pos(2);                % 'y' Annotation Position Function
annotation('textarrow',xapf([0.395 0.395],pos,xlim), yapf([40 5],pos,ylim), 'String',["Less than 1%" "of samples near the" "undesirable 0.40 level"])
xlabel('Denisty')
ylabel('Frequency')
title('Histogram of Density Data')

EDIT — Added annotation object.

.

[Xiao yang]

thank you very much, teacher want students use R or JMP to plot this Histogram

[Xiao yang]

any easy way like use Histogram fun, so many pre-process for plot, that is the diffcuty part.

[Walter Roberson]

@Xiao yang

Calling R from MATLAB is somewhat involved. https://www.mathworks.com/matlabcentral/answers/231000-how-to-run-an-r-function-from-matlab#answer_187337

I would recommend that you skip the MATLAB interface and simply program in R directly.

[Star Strider]

@Xiao yang — My pleasure. You have to have the original data to use any histogram function.

I have no experience with R, and I never heard of JMP.

@Walter Roberson — Thank you!

[Image Analyst]

"teacher want students use R or JMP to plot this Histogram" <== then do so. It's what your teacher wants -- to use R or JMP rather than MATLAB. Your teacher did not say "Ask others to solve the problem for you so you can turn their code in."

This looks like a homework problem. If you have any questions ask your instructor or read the link below to get started:

How do I get help on homework questions on MATLAB Answers? - MATLAB Answers - MATLAB Central

Obviously, if it is homework, we can't give you the full solution because you're not allowed to turn in our code as your own. No offense -- we just don't want you to get into trouble with your teacher.