# Matlab: How to plot a line on a surface object

I made a plot by using a tutorial found on youtube (see figure)

I need to add a vertical line.

This is the code:

```
h = findobj('type','figure');
n = length(h);
dataToPlot = mediaInfraCondRev;
plotHeatMap
```

The last line (plotHeatMap) opens this code:

```
f = figure(n+1);
%Inizialize plotting vectors
buf_len = 1895; % about 30 seconds of data
%index = 1:buf_len; % riga originale trovata su internet
index = time.minsTot(:,1)'; % riga modificata per plottare minuti su asse x
zeroIndex = zeros(size(index));
tcdata = zeroIndex; % rolling vector of temperature readings length buf_len
limits = [min(dataToPlot) max(dataToPlot+0.05)]; %expected range of temps for plotting and color scaling
%set the axes limits and select a 2D (x,z) view (this prevents
%autoscaling
% myAxes = axes ('xLim', [0 buf_len], 'YLim', [0 0.1], 'Zlim', limits,
% 'CLim', limits); % questa e' la riga originale trovata su youtube
myAxes = axes ('xLim', [0 max(index)], 'YLim', [0 0.1], 'Zlim', limits, 'CLim', limits); % questa e' la riga modificata per plottare i minuti su asse x
view(0,0);
grid on;
% Create surface graphics object s to display temperature data in (x,z)
% plane, area color based on temperature readings
% X e Y definiscono le coordinate sul rettangolo. Z definisce la
% superficie sulla griglia e la colora in base a C
% 'XData' 'YData' 'ZData' 'CData'
s = surface (index, [0, 0], [tcdata; zeroIndex], [tcdata; tcdata]);
% Set surface face and edges to fill with CData values, add labels
set(s, 'EdgeColor', 'flat', 'FaceColor', 'flat', 'Parent', myAxes)
% parent 'myAxes' dice di mettere il surface object all'interno degli assi
colorbar
title('Temperature Readings, \circC')
xlabel('Time (minutes)')
zlabel('Temperature(\circC)')
set(f, 'Position', [200 200 890 660])
drawnow;
% INSERIAMO I DATI
tcdata = dataToPlot';
%update plot data and corresponding color
set(s, 'Zdata', [tcdata; zeroIndex], 'Cdata', [tcdata; tcdata])
%force MATLAB to redraw the figure
drawnow;
```

Everything looks perfect, except for one thing: I need to add a vertical line on minute 3 and minute 23. I tried with:

```
line([3 3], get(gca, 'ylim'));
```

This line kind of works on a normal plot (see example)

But it does not show anything if I try on this plot and I can't figure out what to do. Any suggestion?

Please notice: there are some comments in the code that do not apply anymore. The original code was made for a sliding plot: that is, plotting online while collecting data. I slightly adapted it to plot the entire length of data at the end of the experiment.

Thank you for your time, Gluce