How to scale values in y-axis to be 1-100%?

The code below is what I have tried to do. I want to scale the value 200 to become 100% in the plot and the value 100 to become 50%. The x and y values are just made up, I actually need to plot 1440 different values. Help needed! Thanks in advance!

clear
x = [1, 2, 3, 4, 5, 6, 7, 8, 9];
y = [5, 50, 200, 180, 100, 60, 53, 0, 2];
figure
ax = axes;
plot(x,y); 
set(ax, 'YTick', [0:10:100], 'YLim', [0, max(y)]);
ytickformat(ax, 'percentage');
ax.YGrid = 'on';
xlabel('Time (Minutes)');
ylabel('Energy Percentage');

Answer 1

[Mehmed Saad]

clear
x = [1, 2, 3, 4, 5, 6, 7, 8, 9];
y = [5, 50, 200, 180, 100, 60, 53, 0, 2];
figure
ax = axes;
plot(x,y); 
set(ax, 'YTick', [0:10:100], 'YLim', [0, max(y)]);
ytickformat(ax, 'percentage');

Save the yticklabels to a variable as it might be difficult for you to create them

ylbs = ax.YTickLabel;

Set yticks to 0:20:200

ax.YTick = 0:20:200;

and label them from 0 to 100

ax.YTickLabel = ylbs;

ax.YGrid = 'on';
xlabel('Time (Minutes)');
ylabel('Energy Percentage');

Or other way of generating tick label by yourself is

generate number from 0 to 100, convert it to string, split it to cell and add a percentage sign using strcat,

clear
x = [1, 2, 3, 4, 5, 6, 7, 8, 9];
y = [5, 50, 200, 180, 100, 60, 53, 0, 2];
figure
ax = axes;
plot(x,y); 

set(ax, 'YTick', 0:20:200,...
    'YTickLabel',strcat(split(num2str(0:10:100)),'%'),...
    'YLim', [0, max(y)]);


ax.YGrid = 'on';
xlabel('Time (Minutes)');
ylabel('Energy Percentage');

[Thanathip Boonmee]

Hi thank you for your reply. What if I would want to set 100% to be the value of 600? I would now want 600 to be 100%, hence making 200 to be at 33.33%.This 600 will not be in the y varaible though.

[Thanathip Boonmee]

Hey I get it now just need to change

set(ax, 'YTick', 0:60:600,...
    'YTickLabel',strcat(split(num2str(0:10:100)),'%'),...
    'YLim', [0, 600);

Thanks!

[Mehmed Saad]

ylim_max = 600;
yticks_no = linspace(0,ylim_max,11);% Number of ticks you want in plot
set(ax, 'YTick',yticks_no,...
    'YTickLabel',split(strtrim(sprintf(' %%%2.2f',(yticks_no/ylim_max*100)))),...
    'YLim', [0, ylim_max]);

[Thanathip Boonmee]

Thank you, one last question. Is there a way to specify the exact percentage a value is on? I have drawn a red line at the value 53 which is 8.83% of the value 600. I would like to have a way to indicate that it is 8.33% on the y-axis instead of just making a random label which will not look credible.

yline(53,'-r');

[Mehmed Saad]

it is possible but will make the yaxis messy

This is another way to do what you want. see yyaxis for help

[Thanathip Boonmee]

Thank you so much!

[Manish]

How to plot multiple variables with different range of values with same X axis on a single plot with Y axis as percentage?

[DGM]

If they all have a different range of values, then what does "percentage" mean? Percentage of what? If I have two y-data vectors:

y1 = [123 467 783];

y2 = [72 93 21];

What are these in %? In other words, what is the normalizing value? Do both y1 and y2 use the same normalizing value?

Answer 2

[Steven Lord]

Use normalize to normalize your data to the range [0, 100].

x = [1, 2, 3, 4, 5, 6, 7, 8, 9];
y = [5, 50, 200, 180, 100, 60, 53, 0, 2];
yn = normalize(y, "Range", [0 100]);

plot(x, yn); 
yticks(0:10:100)
ytickformat('percentage');

xlabel('Time (Minutes)');
ylabel('Energy Percentage');