2d line plot

Hi all,

I have temperature data for different depths over time. I'd like to display it with a coloured line plot that shows lines at the different depths filled with the temperature gradients over time (see example below). Attached are variables of depth, time and temperature for 0 meters. Anyone can give some help on how to do this?

Thank you in advance!!

Answer 1

[Star Strider]

The patch documentation section on Create Multicolored Line offers one option.

The problem with the data is that the temperature does not vary much with the depth, and then only at the ends —

load('temp0')
load('depth0')
load('time0')
whos

  Name            Size             Bytes  Class       Attributes

  ans             1x34                68  char                  
  cmdout          1x33                66  char                  
  depth0      39577x1             316616  double                
  temp0       39577x1             316616  double                
  time0       39577x1             316648  datetime              

temp0s = [min(temp0) max(temp0)]

temp0s = 1×2

13.0732 29.4457

depth0end = depth0(end);
depth0(end) = NaN; 

figure
patch(time0, -depth0, temp0, 'EdgeColor','interp')
hold on
scatter(time0(end), -depth0end, 5, temp0(end), 'filled', 's')
hold off
cb = colorbar;
cb.Label.String = 'Temperature (°C)';
colormap(turbo)
xlabel('Time')
ylabel('Depth')

figure
plot3(time0, -[depth0(1:end-1); depth0end], temp0, ':k', 'LineWidth',0.25)
hold on
scatter3(time0, -[depth0(1:end-1); depth0end], temp0, 3.5, temp0, 'filled', 's')
hold off
cb = colorbar;
cb.Label.String = 'Temperature (°C)';
colormap(turbo)
grid on
xlabel('Time')
ylabel('Depth')
zlabel('Temperature')

.

[Giulia]

cool! Thank you very much!!

This is similar to the plot I came out with using patch with the following code:

x0 = datenum(time0);
y0 = depth0;
z0= temp0;
x0(end+1)=NaN;
y0(end+1)=NaN;
z0(end+1)=NaN;
c0=z0;

figure
patch(x0,y0,c0, Edgecolor = 'interp');
set(gca, 'YDir','reverse');
colorbar;
caxis([14 16]);
datetick

The only thing I am stuck with is how would I add the other sensors of the mooring on the plot, considering the depth and temp variables for each sensor vary in their lengths (e.g. depth and temp of sensor at 5 m is different from depth and temp of sensor at 10 m)? Any suggestions?

Thanks again!

[Star Strider]

These are the only data presented.

It would probably be necessary for you to use a loop to plot each each sensor in a separate iteration, and use the hold function to plot them together on the same axes. The sensor data would be put in a matrix, then loop through the rows or colums, depending on how the matrix was organised, or if they were different sizes, in a cell array and then index the cell array in the loop.

[Giulia]

Got it, will work on it!

Thank you very much for your help!

[Star Strider]

As always, my pleasure!

Answer 2

[Walter Roberson]

You can use File Exchange contributions such as https://www.mathworks.com/matlabcentral/fileexchange/8597-plot-3d-color-line or https://www.mathworks.com/matlabcentral/fileexchange/19476-colored-line-or-scatter-plot

[Giulia]

Thanks Walter! I saw those file exchanges but not sure how to apply it to my data (quite new to Matlab).

The syntax of the file exchanges has sin and cos (e.g. y=sin(4*pi*x);z=cos(4*pi*x);), don't know how to use it with my data.

Any idea?

Thank you!

[Giulia]

x=datenum(time0)
y=depth0
z=temp0
c=z
W=3

p=clinep(x,y,z,c,W);
colorbar
caxis([14 16])
set(gca, 'YDir','reverse');

This came out using this code. How can I add the other sensors? Thank you!