Plotting two columns from matrix.

8 visualizzazioni (ultimi 30 giorni)
JLV
JLV il 1 Gen 2020
Commentato: JLV il 4 Gen 2020
I am trying to plot Column 4 against Column 10 as a line plot, but only when Columns 8 and 9 are between 0 +/- 0.0005. (Columns 8, 9, 10 are x, y, and z locations).
I would have done this with two if loops which would print the row if the conditions were met. This could have then been plotted. I feel as there are over 400,000 entries this is inefficient (file attached represents a smaller quantity due to size constraints). Prealloaction is not possible as I don't know the size of the final array. What would the best way to go about this?
  2 Commenti
Walter Roberson
Walter Roberson il 1 Gen 2020
In the cases where the conditions are not met, what do you want to do? Are you wanting to do a scatter plot? Are you wanting to plot a disconnected line segment for each consecutive area where the conditions are met? Are you wanting to create a single line plot as if the entries that do not met the condition were not present at all ?
JLV
JLV il 1 Gen 2020
I do not want to use the data at all where the conditions mentioned above is not met.
A scatter plot with a line of best fit will be plotted (Column4 vs Column10).

Accedi per commentare.

Risposta accettata

per isakson
per isakson il 1 Gen 2020
Modificato: per isakson il 1 Gen 2020
See Indexing with Logical Values half way down the page
A starter
%%
M = dlmread('matrix.txt');
%%
is_show = abs(M(:,8))<5e-4 & abs(M(:,9))<5e-4;
%%
figure
plot( M(is_show,10), M(is_show,4), '.' )
  3 Commenti
Walter Roberson
Walter Roberson il 2 Gen 2020
Modificato: per isakson il 3 Gen 2020
x = M(is_show,8);
y = M(is_show,9);
z = M(is_show,4);
Finterp = scatteredInterpolant(x, y, z);
xmin = min(M(:,8));
xmax = max(M(:,8));
ymin = min(M(:,9));
ymax = max(M(:,9));
N = 500;
xrange = linspace(xmin, xmax, N);
yrange = linspace(ymin, ymax, N);
[XGrid, YGrid] = meshgrid(xrange, yrange);
ZGrid = Finterp(XGrid, YGrid);
contourf(XGrid, YGrid, ZGrid);
xlabel('M 8');
ylabel('M 9');
zlabel('M 4');
JLV
JLV il 4 Gen 2020
I will take a look into this and the code deeper when Im back in the office.
Thanks

Accedi per commentare.

Più risposte (0)

Categorie

Scopri di più su Mathematics in Help Center e File Exchange

Tag

Prodotti


Release

R2019b

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by