How to scale a graph

My graph is the at the bottom one (second graph), but it supposed to look like the one above it (first graph). The values (x,y) are the same. Is there a way to scale it like the first graph?

My code

figure(1)

plot(Idx,Deflection,'-b','linewidth',1);

[Walter Roberson]

axis equal

Answer 1

[Andy]

Use this immediately after the plot command to specify how you want the axis to plot.

ylim([-19 0])

Answer 2

[Srivardhan Gadila]

Refer to Specify Axis Limits and specify the limits for X and Y axis.