changing the axis of a plot

x=[0:0.01:20]
y=max(x-10,0)-blsprice(10,10,0.02,0.2,0.2)

plot(x,y)

xlabel('Stock Price at Maturity ($)');
ylabel('Gain ($)');
axis([0 20  -2 10]);

set(gca,'Box','off')

The command above gives me the payoff of an call option, unfortunately the x-axis goes from -2 to 20, but I would like to see the x-axis from 0 to 20, so the starting point should be y=0 and not y=-2. However the plot should still show the y-axis from -2 to 10 and the negative values for y

Answer 1

[Azzi Abdelmalek]

xlim([0 20])
ylim([0 10])

[Locks]

x=[0:0.01:20]
y=max(x-10,0)-blsprice(10,10,0.02,0.2,0.2)

plot(x,y)

xlabel('Stock Price at Maturity ($)');
ylabel('Gain ($)');

xlim([0 20])
ylim([0 10])

set(gca,'Box','off')

but that way, the y axis doesn't goes to -2, it stopps at 0 and although I want the x-axis to start at the point where x is zero and y is zero (and not y=-x and x=0) I also need to see the negative y values

[Walter Roberson]

ylim([-2 10])

[Locks]

like this, the x-axis starts at y=-2, but I would like to have the x-axis starting at y=0

similar to this payoff diagram here:

http://www.google.ch/imgres?imgurl=http://www.optiontradingtips.com/images/payoff-call-option-microsoft.gif&imgrefurl=http://www.optiontradingtips.com/options101/payoff-diagrams.html&h=265&w=379&sz=4&tbnid=GXHZZUDre1D6rM:&tbnh=85&tbnw=122&prev=/search%3Fq%3Doption%2Bpayoff%2Bdiagram%26tbm%3Disch%26tbo%3Du&zoom=1&q=option+payoff+diagram&usg=__7jDpOVhzqKbOmArpR2OwRQ7_NHA=&docid=hfPv6_rETF_dgM&hl=de&sa=X&ei=ZCdPUdrwIuqp4AS6-IDQBQ&ved=0CDwQ9QEwAw&dur=1

[Walter Roberson]

http://www.mathworks.com/matlabcentral/fileexchange/10473

[Locks]

that just gives me a single line, is that correct? I am not sure how I have to handle this code to combine it with mine, could you give me an example?