Issue plotting streamlines (input in ascending order)

Hi all,

I am having an issue plotting some streamlines. I get an error when I attempt to plot my streamlines because it uses interp1 and one of my inputs to streamline is not in "ascending order". I have attached my code and data file. The streamlines should be going from left to right like the vectors in the quiver plot.

Quiver plot looks like this:

Error message is this:

What do I need to do with the inputs to streamline() to makes this work properly?

clc;clear;close all;
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%Set plot stuff:
set(0,'DefaultLineLineWidth',1.5)
% set(0,'DefaultLineColor',[1,1,1])
set(0,'DefaultLineMarkerSize',15)
set(0,'DefaultAxesFontSize',20)
set(0,'DefaultFigureColor',[1,1,1])
set(0,'DefaultTextFontSize',18)
% set(0,'DefaultTextInterpreter','latex')
set(0,'DefaultTextFontName','Times-Roman')
set(0,'DefaultAxesFontName','Times-Roman')
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

runname = 'M.25_0Y_A';

%% Load data
load(['final_data_run1.mat'])
Uavg(Uavg==0) = NaN; % Set null data to NaN
Vavg(Vavg==0) = NaN; % Set null data to NaN

Xi = sort(X(:,1));
Yi = sort(Y(1,:))';

%% Create the combination of xq and yq
[Xq, Yq] = meshgrid(Xi,Yi);

% Interp the data if the x and y data in the file is not in a grid
Uq = rot90(Uavg);
Vq = rot90(Vavg);

%% probe walls (Need rotate these eventually)
ytip   = 4.18-1; % Bottom left vertice of left probe wall
xtip   = -7.703; % Bottom left vertice of left probe wall
width  = 12.7;   % mm
height = 1;      % mm
gap    = 3;      % mm - Distance between probe walls (left end of the walls)

%% New coordinates (origin will be at hte probe tip)
xcenter = xtip;    % X-center point of probe tip
ycenter = ytip-height;  % Y-center point of probe tip   
xtip = xtip-xcenter; % Bottom left vertice of left probe wall
ytip = ytip-ycenter; % Bottom left vertice of left probe wall
Xq   = Xq+ycenter;
Yq   = Yq-xcenter;

%% Plot vectors, probe walls, and streamlines
fig = figure('Renderer', 'painters', 'Position', [1300 10 947 900])
quiver(Yq,-Xq,Vq,-Uq, 1);%, 'LineWidth',2) % Plot vectors


hold on;
yline(0);xline(0); hold on % Plots probe centerlines
l = title({'test_line'}, 'Interpreter', 'none');
title(['Averaged Velocities and Streamlines (',runname,')'])

% % Plot probe walls
rectangle('Position',[xtip,ytip,width,height],'FaceColor','k')
rectangle('Position',[xtip,ytip-gap,width,height],'FaceColor','k')
xlabel('x (mm)')
ylabel('y (mm)')

s      = 0.10;
starty = -2.5:s:2.5;
startx = (min(min(Yq))+.25)*ones(size(starty));

%% Plot Streamlines
% hgridinterp = streamline(Yq,Xq,Vq,Uq,startx,starty); hold on;
hgridinterp = streamline(Yq,-Xq,Vq,-Uq,startx,starty); hold on;
set(hgridinterp,'color','red','linewidth',3);

Answer 1

[Addison Collins]

ANSWER:

I changed the order in which I created the meshgrid, that fixed things.