How can I flip the array data values (based on Y values) so when I am plotting it will be like a mirror plot? (instead of looking like a “mountain” it will look like a “valley”)
Code:
clc
clear
close all
y = [4 5 6 9 10 20 22 25 22 20 15 10 0];
x = 0:12;
data = rot90(cat(1, x, y));
flipData = flip(data);
figure('Name','Data','NumberTitle','off');
plot(data(:,1),data(:,2),'r','LineWidth',2);
figure('Name','Flip Data','NumberTitle','off');
plot(flipData(:,1),flipData(:,2),'r','LineWidth',2);
You can plot max(y) - y:
y2 = max(y) - y;
plot(x, y2, 'r', 'LineWidth', 2);
You can reverse the direction of the axis, so that your graph is upside down, but Y-values are still correct.
y = [4 5 6 9 10 20 22 25 22 20 15 10 0];
x = 0:12;
data = rot90(cat(1, x, y));
figure('Name','Data','NumberTitle','off');
plot(data(:,1),data(:,2),'r','LineWidth',2);
figure('Name','max(y) - y','NumberTitle','off');
y2 = max(y) - y;
plot(x, y2, 'r', 'LineWidth', 2);
figure('Name','ax.YDir reverse','NumberTitle','off');
plot(data(:,1),data(:,2),'r','LineWidth',2);
ax = gca;
ax.YDir = 'reverse';
Related
I have two vectors as follows:
x = 0:5:50;
sir_dB = [50 20 10 5 2 0 -5 -10 -20 -20 -20]
Where x denotes the distance on the x-axis and sir_dB the SNR. For this, I need to generate a color map for a grid of 50 x 60m something similar to this:
based on the value of sir_dB.
I tried the following:
sir_dB = [50 20 10 5 2 0 -5 -10 -20 -20 -20];
xrange = 0:50;
yrange = -30:30;
% create candidate set
[X, Y] = ndgrid(xrange, yrange); % grid of points with a spacing of 1.
candidate_set = [X(:), Y(:)];
test_pt = [0 30];
radius = 5;
% find which of these are within the radius of selected point:
idx = rangesearch(candidate_set, test_pt, radius );
neighborhood = candidate_set(idx{1}, :);
Once I have the neighbors at a radius of 5m, I need to color that part of the grid based on the sir_dB value for a corresponding x value.
I need to have the plot in such a way that for all values of sir_dB greater than 15, the grid should be colored green, yellow for y greater than 0 and red for y greater than -20.
Could someone provide me inputs of how to do this best?
Im not sure exactly what you want, but this should get you started with contourf. I increased the granularity of xrange and yrange to make the radius more smooth but you can change it back if you want.
x = 0:5:50;
sir_dB = [50 20 10 5 2 0 -5 -10 -20 -20 -20];
xrange = 0:0.1:50;
yrange = -30:0.1:30;
% create candidate set
[X, Y] = ndgrid(xrange, yrange); % grid of points with a spacing of 1.
candidate_set = [X(:), Y(:)];
test_pt = [0 30];
r = sqrt((test_pt(1)-X(:)).^2 + (test_pt(2)-Y(:)).^2);
idx = r>5;
snr = nan(size(X));
snr(idx) = interp1(x,sir_dB,X(idx),'linear');
% Some red, yellow, green colors
cmap = [0.8500 0.3250 0.0980;
0.9290 0.6940 0.1250;
0 0.7470 0.1245];
figure();
colormap(cmap);
contourf(X,Y,snr,[-20,0,15],'LineStyle','none');
Plotting the the contour plot alongside the original sir_dB we see that it lines up (assuming you want linear interpolation). If you don't want linear interpolation use 'prev' or 'next' for the interp1 method.
figure();
colormap(cmap);
subplot(2,1,1);
contourf(X,Y,snr,[-20,0,15],'LineStyle','none');
subplot(2,1,2);
plot([0,50],[-20,-20],'-r',[0,50],[0,0],'-y',[0,50],[15,15],'-g',x,sir_dB);
Here is another suggestion, to use imagesc for that. I nothed the changes in the code below with % ->:
x = 0:5:50;
sir_dB = [50 20 10 5 2 0 -5 -10 -20 -20 -20];
xrange = 0:50;
yrange = -30:30;
% create candidate set
[X, Y] = ndgrid(xrange, yrange); % grid of points with a spacing of 1.
% -> create a map for plotting
Signal_map = nan(size(Y));
candidate_set = [X(:), Y(:)];
test_pt = [10 20];
radius = 35;
% find which of these are within the radius of selected point:
idx = rangesearch(candidate_set,test_pt,radius);
neighborhood = candidate_set(idx{1}, :);
% -> calculate the distance form the test point:
D = pdist2(test_pt,neighborhood);
% -> convert the values to SNR color:
x_level = sum(x<D.',2);
x_level(x_level==0)=1;
ColorCode = sir_dB(x_level);
% -> apply the values to the map:
Signal_map(idx{1}) = ColorCode;
% -> plot the map:
imagesc(xrange,yrange,rot90(Signal_map,2))
axis xy
% -> apply custom color map for g-y-r:
cmap = [1 1 1 % white
1 0 0 % red
1 1 0 % yellow
0 1 0];% green
colormap(repelem(cmap,[1 20 15 35],1))
c = colorbar;
% -> scale the colorbar axis:
caxis([-21 50]);
c.Limits = [-20 50];
c.Label.String = 'SNR';
The result:
Code which I wrote for Matlab 2014 but which I want to rewrite it to Matlab 2016 such that it becomes more compact, since it is extranous now
hFig3=figure('Units', 'inches');
hax3_b1=axes('Parent', hFig3);
hax3_b2=axes('Parent', hFig3);
hax3_b3=axes('Parent', hFig3);
hax3_b4=axes('Parent', hFig3);
b1=subplot(2,2,1, hax3_b1);
b2=subplot(2,2,2, hax3_b2);
b3=subplot(2,2,3, hax3_b3);
b4=subplot(2,2,4, hax3_b4);
% Example of common expression
set([b1 b2], 'Units', 'inches'); % http://stackoverflow.com/a/39817473/54964
u=0:0.1:1; y=sin(u); C = [0 2 4 6; 8 10 12 14; 16 18 20 22];
imagesc(b1, u, y, C);
hold on;
plot(b2, u');
histogram(b3, u');
histogram(b4, u);
hold off;
drawnow;
Output is ok
OS: Debian 8.5 64 bit
MATLAB: 2014 but want to convert to 2016
You can simply write:
figure('Units','inches');
b1 = subplot(2,2,1);
b2 = subplot(2,2,2);
b3 = subplot(2,2,3);
b4 = subplot(2,2,4);
or preferably, if you want to have an array of the axes:
figure('Units','inches');
b(1) = subplot(2,2,1);
b(2) = subplot(2,2,2);
b(3) = subplot(2,2,3);
b(4) = subplot(2,2,4);
or use a simple for loop:
figure('Units','inches');
b(1:4) = axes;
for k = 1:numel(b)
b(k) = subplot(2,2,k);
end
In any option you choose there is no need for all the axes commands.
Here is all your 'demo' code:
b(1:4) = axes;
for k = 1:numel(b)
b(k) = subplot(2,2,k);
end
set(b(1:2), 'Units', 'inches');
u=0:0.1:1; y=sin(u); C = [0 2 4 6; 8 10 12 14; 16 18 20 22];
imagesc(b(1), u, y, C);
plot(b(2), u');
histogram(b(3), u');
histogram(b(4), u);
There might be no real need also in the figure command, it depends on what do with it.
If you're just looking for shorter you can eliminate most of the stuff at the beginning. You don't need the figure but I keep it as a matter of habit.
fh = figure;
x = 1:4;
b = arrayfun(#(y) subplot(2,2,y), x, 'UniformOutput',0);
b{1}.Units = 'inches';
b{2}.Units = 'inches';
u=0:0.1:1; y=sin(u); C = [0 2 4 6; 8 10 12 14; 16 18 20 22];
imagesc(b{1}, u, y, C);
plot(b{2}, u');
histogram(b{3}, u');
histogram(b{4}, u);
I have the following picture:
and I want to create a continuous transition. The blue line (-20deg-start) goes until become like (22deg - original), and then goes until become like (60deg-stop).
the code to generate this lines is:
>> clear all
>> x=[0 11 20 34];
>> y=[2 8 17 32];
>> z=[9 20 29 43];
>> v=[16 23 32 43];
>> w=[15 26 35 49];
>> t=[30 40 47 55];
>> figure
>> hold on
>> plot(t,x, t,y, t,z, t,v, t,w)
Is it possible with the help of Matlab?
Thanks!
The following example shows how to do a linear transition between two curves, provided they are both defined on the same set of x values.
x = linspace(0,1,200); %// x values
y1 = log(1+x); %// y values of line 1
y2 = 1-x.^2; %// y values of line 2
c1 = [1 0 0]; %// red
c2 = [0 0 1]; %// blue
plot(x, y1, ':', 'color', c1); %// plot first line
hold on
plot(x, y2, ':', 'color', c2); %// plot second line
tt = linspace(0,1,100); %// define time axis, between 0 and 1. Adjust "100" for smoothness
h = plot(x, y1, '-', 'color', c2); %// moving line. Initially coincides with line 1
for t = tt
y = y1*(1-t) + y2*t;
c = c1*(1-t) + c2*t;
set(h, 'YData', y, 'Color', c); %// update y values and color of moving line
pause(.02) %// adjust ".02" as needed
end
Yes you can (well from what I understand you wish to achieve). You can put all your data into 1 big array and loop through each row and display it, with a small pause between each set of data.
Example:
clear
clc
close all
clear all
x=[0 11 20 34];
y=[2 8 17 32];
z=[9 20 29 43];
v=[16 23 32 43];
w=[15 26 35 49];
t=[30 40 47 55];
%// Put everything in single array
AllArrays = [x;y;z;v;w];
figure
hold all
%// Loop through each rows
for k = 1:size(AllArrays,1)
plot(t,AllArrays(k,:))
%// Make a pause to see output
pause(.5)
end
Output:
Is this what you meant? Or maybe a smoother transition?
In matlab 2014b, I want to make a heatmap and then overlay a line plot using the right y-axis. For example
colormap bone
data = rand(6);
imagesc(data)
ax = gca;
ax.XTick = [1 2 3 4 5 6];
ax.YTick = [1 2 3 4 5 6];
hold on
Now plot a line but use the right y-axis because this has negative values:
x2 = [1 2 3 4 5 6];
y2 = [-0.0001 -0.0997 -0.1997 -0.2995 -0.3994 -0.4995];
plot(x2,y2,'r')
You can make it with a variation of plotyy where the first plot is composed of NaNs.
Here is the code:
hold on
colormap bone
data = rand(6);
imagesc(data)
ax = gca;
yT = ax.YTick;
x2 = [1 2 3 4 5 6];
y2 = [-0.0001 -0.0997 -0.1997 -0.2995 -0.3994 -0.4995];
[ax, ~, h] = plotyy(yT*NaN, yT, x2,y2);
ax(1).YLim = [yT(1)-0.5 yT(end)+0.5];
ax(1).YTick = yT;
ax(1).YColor = [0 0 0];
set(h, 'Color', 'r');
ax(2).YColor = [1 0 0];
ax(2).YTick = -0.5:0.1:0;
and the result:
Best,
I have gone through the related solutions to "Visualizing a toroidal surface in Matlab" but my problem is a little different.I want to be able to visualize segmented toroidal surfaces arranged with vertices attached to each other.Just like a stuck of semi circles with axis along the y-axis in the x-y plane.
`th = linspace( pi/2, -pi/2, 100);
R = 1; %or whatever radius you want
x = -R*cos(th) + 4;
y = -R*sin(th) + 7;
plot(x,y); axis equal;
hold on
x = -R*cos(th) + 4;
y = -R*sin(th) + 9;
plot(x,y); axis equal;
hold on
x = -R*cos(th) + 4;
y = -R*sin(th) + 11;
plot(x,y); axis equal;
hold on
x = -R*cos(th) + 4;
y = -R*sin(th) + 5;
plot(x,y); axis equal
hold on
x = -R*cos(th) + 4;
y = -R*sin(th) + 3;
plot(x,y); axis equal
hold on
x = -R*cos(th) + 4;
y = -R*sin(th) + 1;
plot(x,y); axis equal
hold on
x = -R*cos(th) + 4;
y = -R*sin(th) -1;
plot(x,y); axis equal
hold on
x = -R*cos(th) + 4;
y = -R*sin(th) -3;
plot(x,y); axis equal
hold on
x = -R*cos(th) + 4;
y = -R*sin(th) -5;
plot(x,y); axis equal
hold on
x = -R*cos(th) + 4;
y = -R*sin(th) -11;
plot(x,y); axis equal
hold on
x = -R*cos(th) + 4;
y = -R*sin(th) -9;
plot(x,y); axis equal
hold on
x = -R*cos(th) + 4;
y = -R*sin(th) -7;`
plot(x,y); axis equal`