5.4: Line Plotting
- Page ID
- 55654
\( \newcommand{\vecs}[1]{\overset { \scriptstyle \rightharpoonup} {\mathbf{#1}} } \)
\( \newcommand{\vecd}[1]{\overset{-\!-\!\rightharpoonup}{\vphantom{a}\smash {#1}}} \)
\( \newcommand{\id}{\mathrm{id}}\) \( \newcommand{\Span}{\mathrm{span}}\)
( \newcommand{\kernel}{\mathrm{null}\,}\) \( \newcommand{\range}{\mathrm{range}\,}\)
\( \newcommand{\RealPart}{\mathrm{Re}}\) \( \newcommand{\ImaginaryPart}{\mathrm{Im}}\)
\( \newcommand{\Argument}{\mathrm{Arg}}\) \( \newcommand{\norm}[1]{\| #1 \|}\)
\( \newcommand{\inner}[2]{\langle #1, #2 \rangle}\)
\( \newcommand{\Span}{\mathrm{span}}\)
\( \newcommand{\id}{\mathrm{id}}\)
\( \newcommand{\Span}{\mathrm{span}}\)
\( \newcommand{\kernel}{\mathrm{null}\,}\)
\( \newcommand{\range}{\mathrm{range}\,}\)
\( \newcommand{\RealPart}{\mathrm{Re}}\)
\( \newcommand{\ImaginaryPart}{\mathrm{Im}}\)
\( \newcommand{\Argument}{\mathrm{Arg}}\)
\( \newcommand{\norm}[1]{\| #1 \|}\)
\( \newcommand{\inner}[2]{\langle #1, #2 \rangle}\)
\( \newcommand{\Span}{\mathrm{span}}\) \( \newcommand{\AA}{\unicode[.8,0]{x212B}}\)
\( \newcommand{\vectorA}[1]{\vec{#1}} % arrow\)
\( \newcommand{\vectorAt}[1]{\vec{\text{#1}}} % arrow\)
\( \newcommand{\vectorB}[1]{\overset { \scriptstyle \rightharpoonup} {\mathbf{#1}} } \)
\( \newcommand{\vectorC}[1]{\textbf{#1}} \)
\( \newcommand{\vectorD}[1]{\overrightarrow{#1}} \)
\( \newcommand{\vectorDt}[1]{\overrightarrow{\text{#1}}} \)
\( \newcommand{\vectE}[1]{\overset{-\!-\!\rightharpoonup}{\vphantom{a}\smash{\mathbf {#1}}}} \)
\( \newcommand{\vecs}[1]{\overset { \scriptstyle \rightharpoonup} {\mathbf{#1}} } \)
\( \newcommand{\vecd}[1]{\overset{-\!-\!\rightharpoonup}{\vphantom{a}\smash {#1}}} \)
\(\newcommand{\avec}{\mathbf a}\) \(\newcommand{\bvec}{\mathbf b}\) \(\newcommand{\cvec}{\mathbf c}\) \(\newcommand{\dvec}{\mathbf d}\) \(\newcommand{\dtil}{\widetilde{\mathbf d}}\) \(\newcommand{\evec}{\mathbf e}\) \(\newcommand{\fvec}{\mathbf f}\) \(\newcommand{\nvec}{\mathbf n}\) \(\newcommand{\pvec}{\mathbf p}\) \(\newcommand{\qvec}{\mathbf q}\) \(\newcommand{\svec}{\mathbf s}\) \(\newcommand{\tvec}{\mathbf t}\) \(\newcommand{\uvec}{\mathbf u}\) \(\newcommand{\vvec}{\mathbf v}\) \(\newcommand{\wvec}{\mathbf w}\) \(\newcommand{\xvec}{\mathbf x}\) \(\newcommand{\yvec}{\mathbf y}\) \(\newcommand{\zvec}{\mathbf z}\) \(\newcommand{\rvec}{\mathbf r}\) \(\newcommand{\mvec}{\mathbf m}\) \(\newcommand{\zerovec}{\mathbf 0}\) \(\newcommand{\onevec}{\mathbf 1}\) \(\newcommand{\real}{\mathbb R}\) \(\newcommand{\twovec}[2]{\left[\begin{array}{r}#1 \\ #2 \end{array}\right]}\) \(\newcommand{\ctwovec}[2]{\left[\begin{array}{c}#1 \\ #2 \end{array}\right]}\) \(\newcommand{\threevec}[3]{\left[\begin{array}{r}#1 \\ #2 \\ #3 \end{array}\right]}\) \(\newcommand{\cthreevec}[3]{\left[\begin{array}{c}#1 \\ #2 \\ #3 \end{array}\right]}\) \(\newcommand{\fourvec}[4]{\left[\begin{array}{r}#1 \\ #2 \\ #3 \\ #4 \end{array}\right]}\) \(\newcommand{\cfourvec}[4]{\left[\begin{array}{c}#1 \\ #2 \\ #3 \\ #4 \end{array}\right]}\) \(\newcommand{\fivevec}[5]{\left[\begin{array}{r}#1 \\ #2 \\ #3 \\ #4 \\ #5 \\ \end{array}\right]}\) \(\newcommand{\cfivevec}[5]{\left[\begin{array}{c}#1 \\ #2 \\ #3 \\ #4 \\ #5 \\ \end{array}\right]}\) \(\newcommand{\mattwo}[4]{\left[\begin{array}{rr}#1 \amp #2 \\ #3 \amp #4 \\ \end{array}\right]}\) \(\newcommand{\laspan}[1]{\text{Span}\{#1\}}\) \(\newcommand{\bcal}{\cal B}\) \(\newcommand{\ccal}{\cal C}\) \(\newcommand{\scal}{\cal S}\) \(\newcommand{\wcal}{\cal W}\) \(\newcommand{\ecal}{\cal E}\) \(\newcommand{\coords}[2]{\left\{#1\right\}_{#2}}\) \(\newcommand{\gray}[1]{\color{gray}{#1}}\) \(\newcommand{\lgray}[1]{\color{lightgray}{#1}}\) \(\newcommand{\rank}{\operatorname{rank}}\) \(\newcommand{\row}{\text{Row}}\) \(\newcommand{\col}{\text{Col}}\) \(\renewcommand{\row}{\text{Row}}\) \(\newcommand{\nul}{\text{Nul}}\) \(\newcommand{\var}{\text{Var}}\) \(\newcommand{\corr}{\text{corr}}\) \(\newcommand{\len}[1]{\left|#1\right|}\) \(\newcommand{\bbar}{\overline{\bvec}}\) \(\newcommand{\bhat}{\widehat{\bvec}}\) \(\newcommand{\bperp}{\bvec^\perp}\) \(\newcommand{\xhat}{\widehat{\xvec}}\) \(\newcommand{\vhat}{\widehat{\vvec}}\) \(\newcommand{\uhat}{\widehat{\uvec}}\) \(\newcommand{\what}{\widehat{\wvec}}\) \(\newcommand{\Sighat}{\widehat{\Sigma}}\) \(\newcommand{\lt}{<}\) \(\newcommand{\gt}{>}\) \(\newcommand{\amp}{&}\) \(\definecolor{fillinmathshade}{gray}{0.9}\)We include line plotting in this chapter as we now have the necessary pieces: single-index arrays, and characters. We do not present all the various options since these can readily be found by >> help plot or the documentation. However, we do provide a template which you can use and adapt accordingly.
%A sample plotting script - by Justin Miller
%----------- linear-linear plotting, sine and cosines ---------------
L = 2*pi; %Define the ending angle
N = 100; %Define number of angle segments
xpts = (L/N)*[0:N]; %Define a set of angles for plotting (in radians)
%This could also be done using
%xpts = linspace(0,L,N+1);
sin_values = sin(xpts); %Sine vector of each angle
cos_values = cos(xpts); %Cosine vector of each angle
figure %Create a figure window to draw the plots
plot(xpts,sin_values,'b-') %Plot the sine values in a blue line
hold on %Hold the current figure when plotting
%the next figure
plot(xpts,cos_values,'r--') %Plot the cosine values in a red dashed line
h_sincos_plot = gcf; %Get the handle of the current figure
ha_sincos_axis = gca; %Get the handle of the current axis
axis([0,xpts(end),-1.1,1.1]) %Set the x and y axes [xmin,xmax,ymin,ymax]
set(ha_sincos_axis,'XTick',0:pi/2:2*pi) %Set the location of the x tick marks
set(ha_sincos_axis,'YTick',-1:0.2:1) %Set the location of the y tick marks
set(ha_sincos_axis,'XTickLabel',{'0','pi/2','pi','3*pi/2','2*pi'})
%Set the names of each x tick mark
xlabel('Angle (radians)') %Give a label name to the x axis
ylabel('Trigonomic output') %Give a label name to the y axis
title(['Plot of sin and cos from x = ',num2str(xpts(1)), ...
' to x = ',num2str(xpts(end))])
%Give the figure a title
legend('sin','cos','location','best') %Provide a legend and tell matlab to place
%it in the best location
saveas(h_sincos_plot,'sin_cos.fig') %Take the figure specified by handle
%"h_sincos_plot" and save it
%as "sin_cos.fig" in the working directory
%----------- log-linear plotting, exponential ---------------
clear all
L = 5;
N = 100;
x = (L/N)*[0:N];
y = 2*exp(x);
figure
semilogy(x,y,'b-') %Create a plot where only the y axis is in log scale
%semilogx would plot only the x axis in log scale
xlabel('x')
ylabel('y')
title(['Log-Linear plot of y = 2*exp(x) from x = ',num2str(x(1)), ...
' to x = ',num2str(x(end))])
saveas(gcf,'exp.fig')
%----------- log-log plotting, polynomials ---------------
clear all
L = 10^2;
N = 100;
x= (L/N)*[0:N];
y = 2*(x.^3);
figure
loglog(x,y,'b-') %Create a plot where both axes are in log scale
xlabel('x')
ylabel('y')
title(['Log-Log plot of y = 2x^3 from x = ',num2str(x(1)), ...
' to x = ',num2str(x(end))])
saveas(gcf,'poly.fig')
MATLAB also has extensive "3-D" plotting capabilities.