1 / 22

CSE 123

CSE 123. Plots in MATLAB. Easiest way to plot Syntax: ezplot(fun) ezplot(fun,[min,max]) ezplot(fun2) ezplot(fun2,[xmin,xmax,ymin,ymax]). ezplot(fun) plots the expression fun(x) over the default domain -2p i < x < 2p i .

akira
Download Presentation

CSE 123

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. CSE 123 Plots in MATLAB

  2. Easiest way to plot Syntax: ezplot(fun) ezplot(fun,[min,max]) ezplot(fun2) ezplot(fun2,[xmin,xmax,ymin,ymax]) ezplot(fun) plots the expression fun(x) overthe default domain -2pi < x < 2pi. ezplot(fun,[min,max]) plots fun(x) overthe domain: min < x < max. ezplot(fun2) plots fun2(x,y)= 0 over the default domain -2pi < x <2pi, -2pi < y < 2pi.

  3. Example: >>ezplot('x^3-2*x') >> ezplot('x^3-x',[-5 5])

  4. >> ezplot('x^2-y^4‘[-5,5,-4,4])

  5. plot command: Linear 2-D plot Syntax: plot(X,Y,linespec, ‘PropertyName',PropertyValue, …) LineWidth - specifies the width (in points) of the line. MarkerEdgeColor - specifies the color of the marker or the edge color for filled markers (circle, square, diamond, pentagram, hexagram, and the four triangles). MarkerFaceColor - specifies the color of the face of filled markers. MarkerSize - specifies the size of the marker in units of points.

  6. Examples: x=1:50; y=sin(x*pi/10)+cos(x*pi/10); plot(x,y) Examples: plot(x,y,'--ro')

  7. Example plot(x,y,'-k', 'Linewidth', 5 ) Example plot(x,y,'-kd', 'MarkerEdgeColor',‘g', 'MarkerFaceColor', ‘r' )

  8. Plotting multiple plots on the same figure x=1:50; y1=cos(x*pi/10); y2=sin(x*pi/10); plot(x,y1,x,y2) x=1:50; y1=cos(x*pi/10); y2=sin(x*pi/10); plot(x,y1) hold on plot(x,y2)

  9. Plotting multiple plots on the same figure x=1:50; y1=cos(x*pi/10); y2=sin(x*pi/10); plot(x,y1,’k’) hold on plot(x,y2,’r’ ) plot(x,y1,’k’,x,y2,’r’)

  10. Editing plots with editplot Syntax plotedit on plotedit off

  11. 2 plots: one above the other = 2-by-1 matrix 4 plots: in a 2x2 array = 2-by-2 matrix Subplot(2,1,1) Subplot(2,1,2) subplot command Syntax: subplot(N,M,i) N= number of rowsM= number of columns i= current plot number Notes: *This function does NOT create a plot *It HAS to be used BEFORE the plot function !!!! (2,2,1) (2,2,2) (2,2,3) (2,2,4)

  12. subplot(2,1,1) plot(x,y1); grid on subplot(2,1,2) plot(x,y2,’k’); grid on Plotting multiple plots on the same figure x=1:50; y1=cos(x*pi/10); y2=1000*y1; plot(x,y1,x,y2,’k’); grid on

  13. Plot features: xlabel, ylabel, title, grid x=1:50; y1=cos(x*pi/10); y2=sin(x*pi/10); plot(x,y1,x,y2) xlabel(‘x’); ylabel(‘y’); title(‘Example’) grid on Plot features: text and legend text(15,0.8,’y1’) text(20,-0.2,’y2’) legend(‘y1’,’y2’)

  14. plotyy2-D line plots with y-axes on both left and right side Syntax plotyy(X1,Y1,X2,Y2) plotyy(X1,Y1,X2,Y2) plots X1 versus Y1 with y-axis labeling on the left and plots X2 versus Y2 with y-axislabeling on the right.

  15. Example: >>x=0:0.05:5; y=sin(x.^2); z=cos(x.^2); plotyy(x,y,x,z)

  16. %% Line Plot of a Chirp x=0:0.05:5; y=sin(x.^2); plot(x,y); >> %% Bar Plot of a Bell Shaped Curve x = -2.9:0.2:2.9; bar(x,exp(-x.*x)); >> %% Bar Plot of a Bell Shaped Curve x = -2.9:0.2:2.9; bar(x,exp(-x.*x)); >> %% Stairstep Plot of a Sine Wave x=0:0.25:10; stairs(x,sin(x)); >> %% Errorbar Plot x=-2:0.1:2; y=erf(x); e = rand(size(x))/10; errorbar(x,y,e); >> % Polar Plot t=0:.01:2*pi; polar(t,abs(sin(2*t).*cos(2*t))); >> x = 0:0.1:4; y = sin(x.^2).*exp(-x); stem(x,y)

  17. Logarithmic Plots commands semilogx() plots x data on log axis and y on linear axis semilogy() plots y data on log axis and x on linear axis loglog() plots x and y on logarithmic axes

  18. Logarithmic Plots Example: plot y=e2x >> x=0:0.1:10; >> y=exp(2.*x); >>plot(x,y) >> semilogy(x,y)

  19. Three dimensional plots Three dimensional line plots the simplest form is plot(x,y,z) x,y,z are arrays of equal size containing the locations of data points to plot. Example: x(t)= e-0.2tcos (2t) y(t)= e-0.2tsin(2t) motion of an insect t=0:0.1:10; x=exp(-0.2*t).*cos(2*t); y=exp(-0.2*t).*sin(2*t); plot(x,y) title('\bf 2D plot') xlabel('\bfx') ylabel('\bfy') grid on

  20. Three dimensional plots instead we could plot the variables with plot3() to preserve the time information as well as the 2D position of the object. plot3(x,y,t) t=0:0.1:10; x=exp(-0.2*t).*cos(2*t); y=exp(-0.2*t).*sin(2*t); plot3(x,y,t) title('\bf 3D plot') xlabel('\bfx') ylabel('\bfy') zlabel('\bftime') grid on

  21. Three dimensional plots surface, Mesh and contour plots: such kind of plots represent data that is a function of 2D variables. a user must create three arrays of equal size; Commands: mesh(x,y,z) creates a mesh or wireframe plot where x,y and z are 2D arrays of containing x,y,z values at every point, respectively. surf(x,y,z) creates a surface plot, contour(x,y,z) creates a contour plot, [x,y]=meshgrid(xstart:xinc:xend, ystart:yinc:yend) easily create x and y arrays required for 3D plots to create a 3D plot use meshgrid to create the arrays of x and y values then evaluate the function to plot at each of x,y pairs. finally call the above mentioned functions to create plot.

  22. Three dimensional plots Example: create the mesh plot of the following function over the interval [x,y]=meshgrid(-4:0.1:4); z= exp(-0.5*(x.^2+0.5*(x-y).^2)); mesh(x,y,z);

More Related