Plotting three related data sets with three axes and one line

Hi there,

I will try not to be complicated here as I am not hugely confident with matlab and it's been a while..

I am trying to replicate a graph with my own data. In the other graph, they have three axes, two x (top and bottom) and one y (lhs). The top and left data sets correspond to the bottom axes. I cannot work out how to do this. I have tried creating a transparent axis on top of the first one, but this obviously leaves me with two lines in the final graph.

The below graph is the one I am trying to emulate. I have data for all three (Flow, delta P and percent occlusion). This example does have a second line but it is theory and can thereofre be ignored for my case.

Below is all I can get so far (I know it is hideous and the data is off).

I am using the code below:

figure;

% Create the first axes

hax1 = axes();

p_occn = [3.0 9.2 13.7 16.2 22.2 32.8 41.3 49.0 60.6 66.9 75 83.3 89.1 94.1 97.6]; % Percent Occlusion

delta_p = [6.39 13.16 22.40 26.71 36.21 47.97 65.01 62.99 93.17 99.64 112.59 108.56 119.22 116.57 118.61]; % Delta P

hplot1 = line(p_occn, delta_p);

% Create a transparent axes on top of the first one with it's xaxis on top

% and no ytick marks (or labels)

hax2 = axes('Position', get(hax1, 'Position'), ... % Copy position

'XAxisLocation', 'top', ... % Put the x axis on top

'YAxisLocation', 'right', ... % Doesn't really matter

'xlim', [200 6000], ... % Set XLims to fit our data

'Color', 'none', ... % Make it transparent

'YTick', []); % Don't show markers on y axis

% Plot data with a different x-range here

Q = [211.794 507.77 844.504 1494.07 2057.38 2791.96 3171.93 4593.52 4573.73 5065.67 5754.67 5811.02 5853.12 5996.7 5894.83]; % Flow

hplot2 = line(Q, p_occn, 'Color', 'r', 'Parent', hax2);

% Link the y limits and position together

linkprop([hax1, hax2], {'ylim', 'Position'});

title('Graph of Change in Pressure vs Flow Rate of Graft as Occlusion Worsens');

xlabel(hax1, 'Percent Occlusion (%)');

xlabel(hax2, 'Flow (ml/min)');

ylabel(hax1, 'Delta P (mmHg)');

Any help would be great!

Answer 1

[laurent jalabert]

https://fr.mathworks.com/help/matlab/creating_plots/graph-with-multiple-x-axes-and-y-axes.html