setting xaxis labels to only integers

Hello,

I have a plot where I am trying to make it so that the xaxis is going to be integers and steps of 1.

figure();
           
adcValues_flipped = flip(adcValues);
xlabels_flipped = flip(num2str(x_mm_flipped));
b0_flipped = flip(b0Values);

plot(1:numel(x_mm), adcValues_flipped);
set(gca, 'XTick', 1:numel(x_mm), 'XTickLabel', xlabels_flipped);

Right now the code about gives me an xaxis labels of the following:

    '-4.95'
    ' -4.5'
    '-4.05'
    ' -3.6'
    '-3.15'
    ' -2.7'
    '-2.25'
    ' -1.8'
    '-1.35'
    ' -0.9'
    '-0.45'
    '    0'
    '    0'
    '    0'
    '    0'
    '    0'
    '    0'
    ' 0.45'
    '  0.9'
    ' 1.35'
    '  1.8'
    ' 2.25'
    '  2.7'
    ' 3.15'
    '  3.6'
    ' 4.05'
    '  4.5'
    ' 4.95'
    '  5.4'
    ' 5.85'

Where I would instead like it to be -5, -3, -2, -1, 0, 1, 2, 3, 4, 5, 6 as the xaxis labels and ticks.

Any ideas?

Answer 1

[Mathieu NOE]

hello

using your data I tried to reproduce your plot in figure 1

the modified plot is figure 2

hope it helps !

x_mm = [-4.95
-4.5
-4.05
-3.6
-3.15
-2.7
-2.25
-1.8
-1.35
-0.9
-0.45
0
0
0
0
0
0
0.45
0.9
1.35
1.8
2.25
2.7
3.15
3.6
4.05
4.5
4.95
5.4
5.85];

adcValues_flipped = 1+0.25*sin(x_mm);

% remove duplicates
[x_mm,ind] = unique(x_mm);
adcValues_flipped = adcValues_flipped(ind);

figure(1)  % your plot
plot(x_mm, adcValues_flipped);
set(gca, 'XTick', x_mm, 'XTickLabel', num2str(x_mm));

●

figure(2)  % modified plot
xi = floor(min(x_mm)):1:ceil(max(x_mm));
plot(x_mm, adcValues_flipped);
set(gca, 'XTick', xi, 'XTickLabel', num2str(xi'));

[nina]

Hello,

Thanks for your help -- this won't work though because in the graphs I do not want the zeros collapsed.

Here is an example of what I would want on the right side. You can see that we still have all the zeros

[Mathieu NOE]

ok seems I have already answered this question here :

how to plot all zeros on xaxis? - MATLAB Answers - MATLAB Central

so the only thing you need now is to change the xtick labels for integers ?

[nina]

You've answered an old question, but yes, I am stuck on the xtick labels for integers.

[Mathieu NOE]

so using the same logic , adapted to your new data , this is what I could suggest :

%% create the data
x_mm = [-4.95
-4.5
-4.05
-3.6
-3.15
-2.7
-2.25
-1.8
-1.35
-0.9
-0.45
0
0
0
0
0
0
0.45
0.9
1.35
1.8
2.25
2.7
3.15
3.6
4.05
4.5
4.95
5.4
5.85];

adcValues = 1+0.25*sin(x_mm);  % dummy Adc readings
ind = abs(x_mm)<eps;
adcValues(ind) = 0;  % create the 0 Adc values 

%%  create new x vector
indXzero = find(abs(x_mm)<eps);
xspacing_zero = 1; % delta x spacing between zero values 
xspacing_zero_array = linspace(-xspacing_zero/2,xspacing_zero/2,numel(indXzero));
x_mm_new = x_mm;
x_mm_new(indXzero) = xspacing_zero_array;
% shift left hand side non zero x  values (to have correct spacing)
indleft = (1:min(indXzero)-1);
x_mm_new(indleft) = x_mm(indleft) + xspacing_zero_array(1);
% shift right hand side non zero x  values (to have correct spacing)
indright = (max(indXzero)+1:numel(x_mm));
x_mm_new(indright) = x_mm(indright) + xspacing_zero_array(end);
% plot
xlabels = num2str(x_mm); % plot "true" x_mm values at the specified ticks positions

%% plots 
figure(1)  % your original plot
plot(x_mm_new,adcValues,'-*');
set(gca,'XTick',x_mm_new,'XTickLabel',xlabels);

figure(2)  % modified plot
xi = floor(min(x_mm_new)):1:ceil(max(x_mm_new));
plot(x_mm_new, adcValues,'-*');
set(gca, 'XTick', xi, 'XTickLabel', num2str(xi'));

[nina]

thank you so so much!!!!!!!!!!!!

[Mathieu NOE]

my pleasure !!!!!!!!!!!!!

[nina]

Hey Mathieu,

Ok so getting close but this answer is also incorrect - the axis for the second answer is not giving the actual values for the plot. The dots should be like 0.45, 0.9 etc etc and they’re off quite significantly

[nina]

Figure 1 is correct, but then we are at my original problem where I want the rounded numbers on the x axis.

[Mathieu NOE]

oh yes I am sorry , my bad ,

try this instead : I have now plotted the two on the same figure to make sure the problem is now solved

NB that your "original" plot looks also a bit different as I also apply a unitary x spacing for it (and that is fortunate, otherwise the comparison with the modified plot becomes quite problematic !)

clc
clearvars
%% create the data
x_mm = [-4.95
-4.5
-4.05
-3.6
-3.15
-2.7
-2.25
-1.8
-1.35
-0.9
-0.45
0
0
0
0
0
0
0.45
0.9
1.35
1.8
2.25
2.7
3.15
3.6
4.05
4.5
4.95
5.4
5.85];
adcValues = 1+0.25*sin(x_mm);  % dummy Adc readings
ind = abs(x_mm)<eps;
adcValues(ind) = 0;  % create the 0 Adc values 
%%  create new x vector
indXzero = find(abs(x_mm)<eps);
xspacing_zero_array = 0:numel(indXzero)-1;
x_mm_new = x_mm;
x_mm_new(indXzero) = xspacing_zero_array;
% shift left hand side non zero x  values (to have correct spacing)
indleft = (1:min(indXzero)-1);
x_mm_new(indleft) = x_mm(indleft) + xspacing_zero_array(1);
% shift right hand side non zero x  values (to have correct spacing)
indright = (max(indXzero)+1:numel(x_mm));
x_mm_new(indright) = x_mm(indright) + xspacing_zero_array(end);

% original plot labels 
xlabels = num2str(x_mm); % plot "true" x_mm values at the specified ticks positions

% new plot x labels 
xi_left  = (floor(min(x_mm)):-1);
xi_right  = (1:ceil(max(x_mm)));
xi = [xi_left zeros(1,numel(indXzero)) xi_right] ; 
xi_labels = num2str(xi');
xi_ticks = [xi_left (0:numel(indXzero)-1) xi_right+numel(indXzero)-1] ; 


%% plots 
figure(1)  
% your original plot
subplot(2,1,1)
plot(x_mm_new,adcValues,'-*');
set(gca,'XTick',x_mm_new,'XTickLabel',xlabels);
grid on 

% modified plot
subplot(2,1,2)
plot(x_mm_new,adcValues,'-*');
set(gca, 'XTick', xi_ticks, 'XTickLabel', xi_labels);
grid on 

[nina]

You’re an angel! Thank you 🎉🎉🎉

[Mathieu NOE]

thank you for the nice words !!

Answer 2

[Katy Weihrich]

x_mm = [-4.95 -4.5 -4.05 -3.6 -3.15 -2.7 -2.25 -1.8 -1.35 -0.9 -0.45 0 0 0 0 0 0 0.45 0.9 1.35 1.8 2.25 2.7 3.15 3.6 4.05 4.5 4.95 5.4 5.85]';
% round x_mm to get to integers
x_mm_round = round(x_mm);
% get the absolute of the difference between x_mm and x_round. It should be
%   below a vertein value (in this case 0.2) for all the values that are
%   closest to or are a certain integer
idx = abs(x_mm-x_mm_round) < 0.2;

% remove the ticks that you are not interested in
fig_xticks = 1:numel(x_mm);
fig_xticks = fig_xticks(idx);

% create the corresponding xticklables
fig_xticklabels = num2str(x_mm);  
    % you could insert x_mm_round here instead to get the integers, 
    % but I would not recomment this, since it creates untruthfull labeling of the data
    % if you would like to use integers here you would need to recalculate the tick positions
fig_xticklabels = fig_xticklabels(idx,:);

figure; axes; xlim([1 numel(x_mm)])
set(gca,'XTick',fig_xticks,'XTickLabel',fig_xticklabels,'XTickLabelRotation',90)

●

[Katy Weihrich]

Alternativly, if you would like to keep the ticks ,you can use:

x_mm = [-4.95 -4.5 -4.05 -3.6 -3.15 -2.7 -2.25 -1.8 -1.35 -0.9 -0.45 0 0 0 0 0 0 0.45 0.9 1.35 1.8 2.25 2.7 3.15 3.6 4.05 4.5 4.95 5.4 5.85]';
x_mm_round = round(x_mm);
idx = abs(x_mm-x_mm_round) < 0.2;
fig_xticks = 1:numel(x_mm);
fig_xticklabels = num2str(x_mm); 
fig_xticklabels(~idx,:) = ' ';

figure; axes; xlim([1 numel(x_mm)])
set(gca,'XTick',fig_xticks,'XTickLabel',fig_xticklabels,'XTickLabelRotation',90)

●

[nina]

But how would i do the rounding? Unforunately I already know how to make a plot like you did but am still running into the issue where i want the integers