plotyy: problem with ticks

Hi. I have this graph but I cannot figure out how to adjust the ticks. Can you help me out?

[ax,h1,h2] = plotyy(t,R(:,1),[t,t],[fval,tensione_vapore]);
minimum_left = min(R(:,1));
maximum_left = max(R(:,1));
minimum_right = min(fval);
maximum_right = max(fval);
set(ax(1),'YTick',[minimum_left - 0.1 * minimum_left  : (maximum_left - minimum_left) / 10 : maximum_left + maximum_left * 0.1])
set(ax(2),'YTick',[minimum_right - 0.1 * maximum_left : (maximum_right - minimum_right) / 10 : maximum_right + maximum_right * 0.1])

Edit The last two ticks on the right and left axis should be located at the corners (right and left).

function RP1_senza_loop()
R0 = 20e-6;       
P0 = 101325;
Pmin = 83720.4;
f = 1e6 / 40;
Pvap = 84550;
tspan = [0 500e-6]; % 
options = odeset('RelTol',1e-7,'AbsTol',1e-7);
[t,R] = ode45(@(t,R) DE(t,R,R0,P0,Pmin,f,Pvap), tspan, [R0,0],options);
%
fval = zeros(length(t),1);
for ii = 1 : length(t)
    fval(ii) = P(t(ii),P0,Pmin,f);
end
%
t = t * 1e6;
R = R * 1e6;
tensione_vapore = Pvap * ones(length(t),1);
[ax,h1,h2] = plotyy(t,R(:,1),[t,t],[fval,tensione_vapore]);
xlabel('Time (\mus)')
ylabel(ax(1),'R (\mum)')
ylabel(ax(2),'Pressure (Pa)')
minimum_left = min(R(:,1));
maximum_left = max(R(:,1));
minimum_right = min(fval);
maximum_right = max(fval);
set(ax(1),'YTick',[minimum_left - 0.1 * minimum_left  : (maximum_left - minimum_left) / 10 : maximum_left + maximum_left * 0.1])
set(ax(2),'YTick',[minimum_right - 0.1 * maximum_left : (maximum_right - minimum_right) / 10 : maximum_right + maximum_right * 0.1])
end
%
function Rdot = DE(t,R,R0,P0,Pmin,f,Pvap)
S = 0.05984;
rho = 961.5;
mi = 0.297e-3; % kg / (m * s)
c = 1481;
%
Rdot = zeros(2,1);
Rdot(1) = R(2);
Rdot(2) = -1.5 * R(2) * R(2) / R(1) + 1 / (R(1) * rho) *...
    (Pvap - P(t,P0,Pmin,f) + (P0 - Pvap + 2 * S / R0) *...
    (R0 / R(1))^3 - 2 * S / R(1) - 4 * mi * R(2) / R(1) +...
    R(1) / c * (-3 * R0^3 / R(1)^4 * R(2) * (P0 - Pvap + 2 * S /R0) -...
    derivata(t,P0,Pmin,f)));
end
%
function fval = P(t,P0,Pmin,f)
if (t <= 40e-6)
    fval = P0;
elseif (t > 40e-6) && (t <= 60e-6)
    fval = (P0 + Pmin) / 2 + (P0 - Pmin) / 2 * cos(2 * pi * f * t);
elseif (t > 60e-6) && (t <= 100e-6)
    fval = Pmin;
elseif (t > 100e-6) && (t <= 120e-6)
    fval = (P0 + Pmin) / 2 + (P0 - Pmin) / 2 * cos(2 * pi * f * t);
else
    fval = P0;
end
end
%
function dPdt = derivata(t,P0,Pmin,f)
if (t <= 40e-6)
    dPdt = 0;
elseif (t > 40e-6) && (t <= 60e-6)
    dPdt = (Pmin - P0) * pi * f * sin(2 * pi * f * t);
elseif (t > 60e-6) && (t <= 100e-6)
    dPdt = 0;
elseif (t > 100e-6) && (t <= 120e-6)
    dPdt = (Pmin - P0) * pi * f * sin(2 * pi * f * t);
else
    dPdt = 0;
end
end

I tried with this, but Matlab uses as left axis limit 100. It is too much.

leftlimits = ylim(ax(1));
rightlimits = ylim(ax(2));
set(ax(1),'YTick',[leftlimits(1) : (leftlimits(2) - leftlimits(1)) / 10 : leftlimits(2)])
set(ax(2),'YTick',[rightlimits(1) : (rightlimits(2) - rightlimits(1)) / 10 : rightlimits(2)])

[Mischa Kim]

Unless you tell us how exactly the ticks should be adjusted we cannot help. Also, please attach entire code so we can reproduce.

Answer 1

[Mischa Kim]

Marco, still not quite sure about the end result. How about adding

 set(ax(1),'YLim',[minimum_left, maximum_left])
 set(ax(2),'YLim',[minimum_right, maximum_right])

after you set the tick locations?

[Marco Sammito]

I tweaked your code a little bit and I got this:

I would like only inetegers on the two axes. I tried with round but it did not work:

set(ax(1),'YTick',[0  : (maximum_left - minimum_left) / 10 : round(maximum_left + maximum_left * 0.1)])
set(ax(2),'YTick',[minimum_right - 0.1 * maximum_left : (maximum_right - minimum_right) / 8 : maximum_right + maximum_right * 0.1])
set(ax(1),'YLim',[0, round(maximum_left + 0.1 * maximum_left)])
set(ax(2),'YLim',[minimum_right - 0.02 * minimum_right, maximum_right + 0.1 * maximum_right])

[Image Analyst]

Your step size is not rounded to integers so the in between values are fractions. You need to round this too: (maximum_left - minimum_left) / 10

[Mischa Kim]

Use, instead

 set(ax(1),'YTick',round([minimum_left - 0.1 * minimum_left  : (maximum_left - minimum_left) / 10 : maximum_left + maximum_left * 0.1]))
 set(ax(2),'YTick',round([minimum_right - 0.1 * maximum_left : (maximum_right - minimum_right) / 10 : maximum_right + maximum_right * 0.1]))

Answer 2

[dpb]

   set(ax,{'ylim'},{[minimum_left maximum_left];[minimum_right maximum_right]})

See

doc set  % for details on syntax for multiple values at one go...

Or, of course, just use ylim on each axes handle or the new-fangled methods for a more verbose method.