Matlab plot of several digital signals - matlab

I'm trying to find a way to nicely plot my measurement data of digital signals.
So I have my data available as csv and mat file, exported from an Agilent Oscilloscope. The reason I'm not just taking a screen shot of the Oscilloscope screen is that I need to be more flexible (make several plots with one set of data, only showing some of the lines). Also I need to be able to change the plot in a month or two so my only option is creating a plot from the data with a computer.
What I'm trying to achieve is something similar to this picture:
The only thing missing on that pic is a yaxis with 0 and 1 lines.
My first try was to make a similar plot with Matlab. Here's what I got:
What's definitely missing is that the signal names are right next to the actual line and also 0 and 1 ticks on the y-axis.
I'm not even sure if Matlab is the right tool for this and I hope you guys can give me some hints/a solution on how to make my plots :-)
Here's my Matlab code:
clear;
close all;
clc;
MD.RAW = load('Daten/UVLOT1 debounced 0.mat'); % get MeasurementData
MD.N(1) = {'INIT\_DONE'};
MD.N(2) = {'CONF\_DONE'};
MD.N(3) = {'NSDN'};
MD.N(4) = {'NRST'};
MD.N(5) = {'1V2GD'};
MD.N(6) = {'2V5GD'};
MD.N(7) = {'3V3GD'};
MD.N(8) = {'5VGD'};
MD.N(9) = {'NERR'};
MD.N(10) = {'PGD'};
MD.N(11) = {'FGD'};
MD.N(12) = {'IGAGD'};
MD.N(13) = {'GT1'};
MD.N(14) = {'NERRA'};
MD.N(15) = {'GT1D'};
MD.N(16) = {'GB1D'};
% concat vectors into one matrix
MD.D = [MD.RAW.Trace_D0, MD.RAW.Trace_D1(:,2), MD.RAW.Trace_D2(:,2), MD.RAW.Trace_D3(:,2), ...
MD.RAW.Trace_D4(:,2), MD.RAW.Trace_D5(:,2), MD.RAW.Trace_D6(:,2), MD.RAW.Trace_D7(:,2), ...
MD.RAW.Trace_D8(:,2), MD.RAW.Trace_D9(:,2), MD.RAW.Trace_D10(:,2), MD.RAW.Trace_D11(:,2), ...
MD.RAW.Trace_D12(:,2), MD.RAW.Trace_D13(:,2), MD.RAW.Trace_D14(:,2), MD.RAW.Trace_D15(:,2)];
cm = hsv(size(MD.D,2)); % make colormap for plot
figure;
hold on;
% change timebase to ns
MD.D(:,1) = MD.D(:,1) * 1e9;
% plot lines
for i=2:1:size(MD.D,2)
plot(MD.D(:,1), MD.D(:,i)+(i-2)*1.5, 'color', cm(i-1,:));
end
hold off;
legend(MD.N, 'Location', 'EastOutside');
xlabel('Zeit [ns]'); % x axis label
title('Messwerte'); % title
set(gca, 'ytick', []); % hide y axis
Thank you guys for your help!
Dan
EDIT:
Here's a pic what I basically want. I added the signal names via text now the only thing that's missing are the 0, 1 ticks. They are correct for the init done signal. Now I just need them repeated instead of the other numbers on the y axis (sorry, kinda hard to explain :-)

So as written in my comment to the question. For appending Names to each signal I would recommend searching the documentation of how to append text to graph. There you get many different ways how to do it. You can change the position (above, below) and the exact point of data. As an example you could use:
text(x_data, y_data, Var_Name,'VerticalAlignment','top');
Here (x_data, y_data) is the data point where you want to append the text and Var_Name is the name you want to append.
For the second question of how to get a y-data which contains 0 and 1 values for each signal. I would do it by creating your signal the way, that your first signal has values of 0 and 1. The next signal is drawn about 2 higher. Thus it changes from 2 to 3 and so on. That way when you turn on y-axis (grid on) you get values at each integer (obviously you can change that to other values if you prefer less distance between 2 signals). Then you can relabel the y-axis using the documentation of axes (check the last part, because the documentation is quite long) and the set() function:
set(gca, 'YTick',0:1:last_entry, 'YTickLabel',new_y_label(0:1:last_entry))
Here last_entry is 2*No_Signals-1 and new_y_label is an array which is constructed of 0,1,0,1,0,....

For viewing y axis, you can turn the grid('on') option. However, you cannot chage the way the legends appear unless you resize it in the matlab figure. If you really want you can insert separate textboxes below each of the signal plots by using the insert ->Textbox option and then change the property (linestyle) of the textbox to none to get the exact same plot as above.

This is the end result and all my code, in case anybody else wants to use the good old ctrl-v ;-)
Code:
clear;
close all;
clc;
MD.RAW = load('Daten/UVLOT1 debounced 0.mat'); % get MeasurementData
MD.N(1) = {'INIT\_DONE'};
MD.N(2) = {'CONF\_DONE'};
MD.N(3) = {'NSDN'};
MD.N(4) = {'NRST'};
MD.N(5) = {'1V2GD'};
MD.N(6) = {'2V5GD'};
MD.N(7) = {'3V3GD'};
MD.N(8) = {'5VGD'};
MD.N(9) = {'NERR'};
MD.N(10) = {'PGD'};
MD.N(11) = {'FGD'};
MD.N(12) = {'IGAGD'};
MD.N(13) = {'GT1'};
MD.N(14) = {'NERRA'};
MD.N(15) = {'GT1D'};
MD.N(16) = {'GB1D'};
% concat vectors into one matrix
MD.D = [MD.RAW.Trace_D0, MD.RAW.Trace_D1(:,2), MD.RAW.Trace_D2(:,2), MD.RAW.Trace_D3(:,2), ...
MD.RAW.Trace_D4(:,2), MD.RAW.Trace_D5(:,2), MD.RAW.Trace_D6(:,2), MD.RAW.Trace_D7(:,2), ...
MD.RAW.Trace_D8(:,2), MD.RAW.Trace_D9(:,2), MD.RAW.Trace_D10(:,2), MD.RAW.Trace_D11(:,2), ...
MD.RAW.Trace_D12(:,2), MD.RAW.Trace_D13(:,2), MD.RAW.Trace_D14(:,2), MD.RAW.Trace_D15(:,2)];
cm = hsv(size(MD.D,2)); % make colormap for plot
figure;
hold on;
% change timebase to ns
MD.D(:,1) = MD.D(:,1) * 1e9;
% plot lines
for i=2:1:size(MD.D,2)
plot(MD.D(:,1), MD.D(:,i)+(i-2)*2, 'color', cm(i-1,:));
text(MD.D(2,1), (i-2)*2+.5, MD.N(i-1));
end
hold off;
%legend(MD.N, 'Location', 'EastOutside');
xlabel('Zeit [ns]'); % x axis label
title('Messwerte'); % title
% make y axis and grid the way I want it
set(gca, 'ytick', 0:size(MD.D,2)*2-3);
grid off;
set(gca,'ygrid','on');
set(gca, 'YTickLabel', {'0'; '1'});
ylim([-1,(size(MD.D,2)-1)*2]);

Related

Scatter with line segments

I really like scatter()'s ability to automatically color points based on some vector of values, I just want to add colored lines between the points.
The plot in question has time on x-axis, monte-carlo number on y-axis, and then some measured value as the color vector (e.g. number of cars seen in a video frame).
Basically, each point is an update in the system. So calling scatter(time,monte_carlo_number,[],color_vec) plots the points at which there is an update in the system, with color representing some value. This is great, but I would like to add line segments that connect these points, each segment matching the color specified by color_vec.
Basic working example
% Create example data
data = table();
data.time = randsample(1:100, 1000, true)';
data.mc = randsample(1:50, 1000, true)'; % actual monte-carlo run number labels are sorted
data.color_value = randsample(1:10, 1000, true)';
% Create the scatter plot
scatter(data.time, data.mc, [] , data.color_value, 'filled')
colorbar('Ticks', unique(data.color_value))
% Always label your axes
xlabel('Time (s)')
ylabel('Monte-Carlo Run Number')
Below is a screen-shot of what this code might produce. If color_value is the number of cars seen in a video frame, we can see each time this value is updated via the points. However, it is easier for humans to read this plot if there were lines connecting each point to the next with the correct color. This demonstrates to the viewer that this value continues on in time until the next update.
Something like this? I changed the number of samples to 100, and it is already quite a mess, so I don't think this is going to the viewer understand what's plotted.
% Create example data
data = table();
np = 100;
data.time = randsample(1:100, np, true)';
data.mc = randsample(1:50, np, true)'; % actual monte-carlo run number labels are sorted
data.color_value = randsample(1:10, np, true)';
vals = unique(data.color_value).';
cmap = parula(numel(vals));
colors = [];
for k = 1:numel(vals)
ind = find(data.color_value == vals(k));
data_sel{k} = sortrows(data(ind,:));
colors(k,:) = cmap(k,:);
end
figure(1); clf;
% Create the scatter plot
scatter(data.time, data.mc, [] , data.color_value, 'filled')
hold on
for k = 1:numel(vals)
plot(data_sel{k}.time, data_sel{k}.mc, 'Color',colors(k,:))
end
colorbar('Ticks', unique(data.color_value))
% Always label your axes
xlabel('Time (s)')
ylabel('Monte-Carlo Run Number')

Logarithmic x axis in a stackplot MatLab

I'm trying to make a stack plot from a table, to present several variables with the same x-axis. however, I want the x-axis to be logarithmic. I couldn't find any way in stackplot documentation. Does anyone have any suggestions on how I can solve this?
I have tried using subplots instead, however, that way my graphs would not fit all on one page and I would have a lot of white space between the subplots. Therefore, I chose stackplot to make it more nice and less space-consuming.
tbl = readtable('usage.csv');
newYlabels = {'Heating (kWh/year)','Cooling (kWh/year)','Electricity (kWh/year)'};
stackedplot(tbl,[{2:16},{17:27},{28:35}],'XVariable',[1],'DisplayLabels',newYlabels);
Here is the output of the code:
Here is an image of what I'm trying to make, but the x-axis needs to be the real variable (\beta) in logarithmic scale
stackedplot has unfortunately no logarithmic axes option, and since it creates a StackedAxes instead of a normal Axes object, there is no way to changes this.
If the only reason you want to use stackedplot is to have less white-space, you might want to check out tight_subplot on the Matlab FEX. This would allow you to just do: set(ax, 'XScale', 'log').
You can however take the log of your x-data, and add that to the table:
tbl = readtable('outages.csv'); % sample data
tbl = sortrows(tbl, 'OutageTime'); % sort by date
% make x vector; for example just row numbers
x = (1:size(tbl,1)).';
xlog = log10(x);
% add x to table
tbl.Xlog = xlog;
tbl.X = x;
% plot normal x
f = figure(1); clf;
s = stackedplot(tbl, {'Loss'}, 'XVariable', 'X');
xlabel('rows');
% plot log(x)
f = figure(2); clf;
s = stackedplot(tbl, {'Loss'}, 'XVariable', 'Xlog');
xlabel('log(rows)')
Normal:
Log:

Plot digitization in MATLAB using ginput

I'm trying to digitize this image using MATLAB:
I have the following script:
%// Get data from plot
clear all; close all;
%// Input
fname = 'Fig15a.PNG';
xvec = [1e3:1:1e8];
yvec = [1e-4:1:1e-1];
xt = [1e3 1e4 1e5 1e6 1e7 1e8];
yt = [1e-4 1e-3 1e-2 1e-1];
%// Read and plot the image
im = imread(fname);
figure(1), clf
im = im(end:-1:1,:,:);
image(xvec,yvec,im)
axis xy;
grid on;
%// Set ticks
set(gca,'xtick',xt,'ytick',yt); %// Match tick marks
%// Collect data
[x,y] = ginput; %// Click on points, and then hit ENTER to finish
%// Plot collected data
hold on; plot(x,y,'r-o'); hold off;
%// Then save data as:
save Fig15a.mat x y
The script works fine
Is there a way I can change the x and y axes to a log scale ?
I have tried adding the following code in different places without luck:
%// Set Log scale on x and y axes
set(gca,'XScale','log','YScale','log');
Below's a proof of concept that should get you on the right track. I have replaced things in your original code with what I consider "good practices".
function q36470836
%% // Definitions:
FIG_NUM = 36470836;
%% // Inputs:
fname = 'http://i.stack.imgur.com/2as4t.png';
xt = logspace(3,8,6);
yt = logspace(-4,-1,4);
%% // Init
figure(FIG_NUM); clf
% Read and plot the image
im = imread(fname);
hIMG = imshow(im); axis image;
%// Set ticks
hDigitizer = axes('Color','none',...
'XLim',[xt(1) xt(end)],'YLim',[yt(1) yt(end)],...
'XScale','log','YScale','log',...
'Position',hIMG.Parent.Position .* [1 1 696/785 (609-64+1)/609]);
uistack(hDigitizer,'top'); %// May be required in some cases
grid on; hold on; grid minor;
%// Collect data:
[x,y] = ginput; %// Click on points, and then hit ENTER to finish
%// Plot collected data:
scatter(x,y,'o','MarkerEdgeColor','r');
%// Save data:
save Fig15a.mat x y
Here's an example of what it looks like:
Few notes:
xt, yt may be created in a cleaner fashion using logspace.
It is difficult (possibly impossible) to align the digitization grid with the image correctly, which would inevitably result in errors in your data. Though this can be helped in the following scenarios (for which you will require a vector graphics editor, such as the freeware InkScape):
If, by any chance, you got this image from a PDF file, where it appears as a vector image (you can test this by zooming in as much as you like without the chart becoming pixelated; this seems to be your case from the way the .png looks), you would be better off saving it as a vector image and then you have two options:
Exporting the image to a bitmap with a greatly increased resolution and then attempting the digitization procedure again.
Saving the vector image as .svg then opening the file using your favorite text editor and getting the exact coordinates of the points.
If the source image is a bitmap (as opposed to vector graphic), you can "trace the bitmap", thus converting it to vectoric, then #GOTO step 1.
This solution doesn't (currently) support resizing of the figure.
The magic numbers appearing in the Position setting are scaling factors explained in the image below (and also size(im) is [609 785 3]). These can technically be found using "primitive image processing" but in this case I just hard-coded them explicitly.
You can plot in double logarithmic scale with
loglog(x,y);
help loglog or the documentation give additional information.
For a single logarithmic scale use
semilogx(x,y);
semilogy(x,y);

MATLAB textbox in a constant position on top of spinning 3D plot?

I'm trying to have a textbox in MATLAB on a spinning plot, but I don't want the textbox to change its position relative to the figure. I thought that 'units','normalized' in the text function would do it, but it's not quite working, as the example below illustrates. I suppose I could use uicontrol but I'd like to use Greek letters and I can't get uicontrol looking quite as good as text. The following example recreates my problem. You'll notice the text box moves as the plot spins, but I'd like it to just stay in the top left region where it starts. Thank you!
part_x = rand(1000,3)-.5; %generate random 3D coordinates to scatter
fig1 = figure;
scatter3(part_x(:,1), part_x(:,2), part_x(:,3))
axis equal vis3d
axis([-1 1 -1 1 -1 1])
set(fig1,'color','w')
for tau = 1:150
view(tau+20,30); %spin the plot
pause(.01)
if tau~=1; delete(tau_text); end; %delete the previous text if it exists
tau_text = text(.1,.7,...
['\tau = ',num2str(tau)],...
'units','normalized',... %text coordinates relative to figure?
'Margin',3,... %these last 3 lines make it look nice
'edgecolor','k',...
'backgroundcolor','w');
end
Several things:
1) As you found out - using an annotation object instead of text object is the way to go. The difference is explained very nicely here.
2) You should only create the annotation once and then modify its string instead of deleting and recreating it on every iteration.
Finally:
part_x = rand(1000,3)-.5;
fig1 = figure;
scatter3(part_x(:,1), part_x(:,2), part_x(:,3))
axis equal vis3d
axis([-1 1 -1 1 -1 1])
set(fig1,'color','w')
%// Create the text outside the loop:
tau_text = annotation('textbox',[0.2 0.8 0.1 0.05],...
'string','\tau = NaN',...
'Margin',4,...
'edgecolor','k',...
'backgroundcolor','w',...
'LineWidth',1);
for tau = 1:150
view(tau+20,30);
pause(.01)
set(tau_text,'String',['\tau = ',num2str(tau)]); %// Modify the string
end
Notes:
1) It is interesting to note that #Otto's suggestion of using legend results in the creation of an axes (because this is what a legend object is - an axes with annotation children). You could then position the legend manually, and get its location using either get(gco,'position') (assuming it was the last thing you clicked) or more generally get(findobj('tag','legend'),'position'). Afterwards, whenever you create the legend, you can just set its position to the one you previously got. You could also get rid of the line\marker inside the legend by deleting the appropriate child of type line from the legend, e.g.:
ezplot('sin(x)');
hLeg = legend('\tauex\tau');
delete(findobj(findobj('Tag','legend'),'Type','line'));
hA1 = findobj(findobj('Tag','legend'),'Type','text');
set(hA1,'Position',[0.5,0.5,0],'HorizontalAlignment','center');
It is of course also possible to manipulate the legend's String using its handle (hA1) directly.
2) This post on UndocumentedMatlab discusses the behavior of annotation objects and some undocumented ways to manipulate them.
You could use
legend(['\tau = ',num2str(tau)],'Location','NorthWestOutside')
Thank you Dev-iL! annotation works much better for this purpose than text and the implementation is very similar. And thank you for the advice on modifying the string rather than deleting an recreating it.
Here is the code now, working much better:
part_x = rand(1000,3)-.5; %generate random 3D coordinates to scatter
fig1 = figure;
scatter3(part_x(:,1), part_x(:,2), part_x(:,3))
axis equal vis3d
axis([-1 1 -1 1 -1 1])
set(fig1,'color','w')
tau_text = annotation('textbox',[0.2 0.8 0.1 0.05],...
'string','',...
'Margin',4,... %these last 4 lines make it look nice
'edgecolor','k',...
'backgroundcolor','w',...
'LineWidth',1);
for tau = 1:150
view(tau+20,30); %spin the plot
pause(.01)
set(tau_text,'String',['\tau = ',num2str(tau)]);
end

How do I reach first and second plots from bode()

I know how to create the Bode plots with bode() function. If I want to overlap two or more systems frequency responses, I use
bode(sys1,sys2,...)
or
hold on
When I want to reach the plot in order to put a legend with text(), for instance, is easy to reach the second plot. Something like the figure pointer always returns to the second plot (phase graph).
i.e., if try these lines:
G = tf([1],[1 6]); figure(1); bode(G); text(10,-20,'text');
G = tf([1],[1 6]); figure(2); bode(G); text(10,-20,'text');
when I return to the first figure, with figure(1), and try
figure(1); text(10,-20,'text')
legend is displayed in the second plot (Phase plot)
I try these other lines:
P = bodeoptions; % Set phase visiblity to off
P.PhaseVisible = 'off';
G = tf([1],[1 6]);
figure(1); bode(G,P); text(10,-20,'text');
figure(1); text(10,-20,'text');
As you can see, even I turn off the phase plot visiblity, the legend is not displayed.
Essentialy, my question is, how do I reach first and second plots, one by one? I tried with subplot(), but it is pretty clear this is not the way Matlab traces these plots.
Thanks in advance.
It all comes to getting into upper plot, since after bodeplot command the lower one is active. Intuitively one would want to call subplot(2,1,1), but this just creates new blank plot on top of if. Therefore we should do something like this:
% First, define arbitrary transfer function G(s), domain ww
% and function we want to plot on magnitude plot.
s = tf('s');
G = 50 / ( s*(1.6*s+1)*(0.23*s+1) );
ww = logspace(0,3,5000);
y = 10.^(-2*log10(ww)+log10(150));
hand = figure; % create a handle to new figure
h = bodeplot(G,ww);
hold on;
children = get(hand, 'Children') % use this handle to obtain list of figure's children
% We see that children has 3 objects:
% 1) Context Menu 2) Axis object to Phase Plot 3) Axis object to Magnitude Plot
magChild = children(3); % Pick a handle to axes of magnitude in bode diagram.
% magChild = childern(2) % This way you can add data to Phase Plot.
axes(magChild) % Make those axes current
loglog(ww,y,'r');
legend('transfer function','added curve')
you can get magnitude and phase data separately for each system using:
[mag,phase] = bode(sys,w)
now you can use subplot or plot to plot the diagram you want.
The only solution I was able to perform is taking into account axis position. It is not very clean but it works.
Here is the code to select mag plot:
ejes=findobj(get(gcf,'children'),'Type','axes','visible','on');
posicion=get(ejes,'pos');
tam=length(posicion);
for ii=1:tam
a=posicion{ii}(2);
vectorPos(ii)=a;
end
[valorMax,ind]=max(vectorPos); % min for choosing the phase plot
axes(ejes(ind))