How can I add the percentage result on plotted figure ?

Hi I have this code. Everything is fine, the code plots wavelength-intensity relationship according to the csv data and it labels the peak point. So my question is I have a formula for the percentage. It's (intensity/intensity_max)*100 so I need to add a text code that will solve the equation and it will show the result for every if and elseif state on the figure.

Answer 1

[Alan Stevens]

doc text

[Onur Hakverdi]

I know but I couldn't make it.

[Alan Stevens]

"... I need to add a text code that will solve the equation..." What equation?

Which are the actual intensities you want to put onto the graph? Do you mean the limits of each if elsif ... etc section? For example, the vaues 333.8 and 345.1 for the Cu_I section?

[Onur Hakverdi]

Hi the equation for the percentage is that (intensity/intensity_max)*100 so for example in the Cu_I section intensity max 345.1 lets say our intensity value 340 so 340/345.1*100 our percentage value. I want this calculation in all sections and I want to text in the figure as a numerical result.

[Alan Stevens]

You have intensity values at all waveengths!

Since the first "if" section just considers intensity_max, not intensity, I guess you want to calculate

(intensity_max/345.1)*100.

If so, then do something like:

pc = (intensity_max/intensity)*100;

then after your plot command do something like

text(x,y,num2str(pc))

where you choose x and y as suitable coordinates to place the value where you want on the graph.

[Onur Hakverdi]

my x and y coordinates are undefined so I don't know the values because it's randomly data.

Answer 2

[Steven Lord]

FYI if you want the only marker to be at the highest point you could use MarkerIndices rather than plotting two separate lines.

x = 1:100;
y = 20*rand(size(x));
[~, ind] = max(y);
plot(x, y, 'o-', 'MarkerFaceColor', 'r', 'MarkerIndices', ind)

I'm not 100% sure of what you're looking for, but do you want to have lines across the plot indicating when the values are in certain ranges?

figure
plot(x, y, 'o-', 'MarkerFaceColor', 'r', 'MarkerIndices', ind)
hold on
yline(10, 'Label', 'halfway point');
yline(5, 'Label', 'quarter of the way through')

[Onur Hakverdi]

hi I didn't mean it. Let say for if statment 1. Our intensity value is 340 and in our condition max intensity 345 so How can we calculate percantage of this 340/345*100 Am I right ? so I want to text this calculation result on figure for each if elseif statement.

[Onur Hakverdi]

inside the plot or outside of the plot doesn't matter.

[Steven Lord]

For the example plot I created there are 100 points. Do you want a label on each and every one of those 100 points? If not, what's the rule for which points or Y coordinates get labels?

Can you sketch out on paper what type of plot you're hoping to see and attach a picture of that sketch to this discussion? This is a situation where I think a picture really would be worth a thousand words.

[Onur Hakverdi]

No I don't want any labelling. I just only want to text percantage of intensity value on figure. So our data intensity value 340 it is approriate for condition 1 so in this condition intensity max 345 so the percentage = (340/345)*100 = percentage so I want to exit on figure. Location is not matter. For example, we can print on inside the figure or outside of the figure.

[Onur Hakverdi]

like this one in terms of A simple plot from 1 to 10 I just want to write The percentage of intensity is bla bla. I tried text command but my data is random data. Thus, I've faced problem with the x and y coordinates because my coordinates are not known, I mean they are changable.

[Steven Lord]

So you're trying to find a "good" place to put the annotation, one where ideally it won't overlap any of the data or will overlap only "uninteresting" parts of the data?

I would probably put that as the title of my plot, where it would normally be placed directly above the plot. If you had to put it inside the axes, I would consider making a legend for the plot and let MATLAB figure out where to put it.

x = 1:100;
y = 20*rand(size(x));
[maxY, ind] = max(y);
plot(x, y, 'o-', 'MarkerFaceColor', 'r', 'MarkerIndices', ind)
title("The maximum value of y is " + maxY + " at location " + x(ind))
legend("This is the legend approach for" + newline + "representing " + maxY, ...
    'Location', 'best')

[Onur Hakverdi]

yeah something like this but there is a formula for percentage I will do in for every if statement formula = (intensity/intensity_max)*100 I want to text this calculation result on my figure where it can inside or outside of the figure. So lets say our intensity data received as 340 so it fits with the condition 1 and it will use (intensity/intensity_max)*100 this formula 340/345*100 so result will be published on the figure.

[Steven Lord]

Ah, so you're unsure how to construct the string that will be passed into either title or legend?

Use sprintf to format the string exactly how you want it to appear. See the sprintf documentation page for many examples of how to use that function, then call title or legend like I did with that string as the input.

[Onur Hakverdi]

I tried text command but It didn't work because my coordinates are unknown so they are randomly created it changes when the data received. txt = (intensity/intensity_max)*100; text(x,y,txt) but didn't work.

[Walter Roberson]

txt = sprintf('%.2f', (intensity/intensity_max)*100);
text(x,y,txt)

[Onur Hakverdi]

hi problem with the x y coordinates because my coordinates are unknown it depends the data.

[Walter Roberson]

txt = sprintf('ratio = %.2f', (intensity/intensity_max)*100);
title(txt)