1、4.4 3-D Line Plots Theplot3function Thefplot3function1 The plot3 Functionx=0.2,1.8,2.5;y=1.3,2.8,1.1;z=0.4,1.2,1.6;plot3(x,y,z)grid onaxis(0,3,1,3,0,2);xy(1)Basic Syntaxplot3(x,y,z)The x,y and z are both vectors with equal length,which store x-coordinate,y-coordinate and z-coordinate of each point.E
2、xample1 Drawing a broken line.=+zty t t t tx t t t)cos sin(0 10sin cost=linspace(0,10*pi,200);x=sin(t)+t.*cos(t);y=cos(t)-t.*sin(t);z=t;subplot(1,2,1)plot3(x,y,z)grid onsubplot(1,2,2)plot3(x(1:4:200),y(1:4:200),z(1:4:200)grid onExample2 Drawing a helical line.1 The plot3 Function(2)Other forms of x,
3、y and zplot3(X,Y,Z)If Specify x,y and z as all matrices of the same shape,plot lines with the correspondingcolumn elements of X,Y and Z,and the number of curves is equal to that of thecolumns of the matrix.If Specify at least one of X,Y,or Z as a matrix,and the others as vectors.Each of X,Y,and Z mu
4、st have at least one dimension that is same size.t=0:0.01:2*pi;t=t;x=t,t,t,t,t;y=sin(t),sin(t)+1,sin(t)+2,sin(t)+3,sin(t)+4;z=t;plot3(x,y,z)t=0:0.01:2*pi;x=t;y=sin(t);sin(t)+1;sin(t)+2;sin(t)+3;sin(t)+4;z=t;plot3(x,y,z)Example 3 Plot 5 sine curves at different positions in 3-D space.This graph can a
5、lso be plotted using following codes.Plot a set of coordinates of points in 3-D space,specified by each XYZ triplet.It will plot n curves response to n vectors.t1=0:0.01:1.5*pi;t2=0:0.01:2*pi;t3=0:0.01:3*pi;plot3(t1,sin(t1),t1,t2,sin(t2)+1,t2,t3,sin(t3)+2,t3)1 The plot3 Function(3)Use XYZ triplet to
6、 specify multiple sets of coordinates.plot3(x1,y1,z1,x2,y2,z2,xn,yn,zn)Example 4 Plot three sine curves with different length.1 The plot3 Function(4)With optional argumentplot3(X,Y,Z,LineSpec)Argument LineSpec specify line styles,markers,and colors.Example 5 Create curves according to the parametric
7、 equation.x ty tz tt=cossin2,0 6 t=0:pi/50:6*pi;x=cos(t);y=sin(t);z=2*t;plot3(x,y,z,p)xlabel(X),ylabel(Y),zlabel(Z);grid onSyntaxfplot3(funx,funy,funz,tlims)If coordinates of the curve are defined by parametric equations of t,arguments funx,funy,and funz are parametric functions for x,y,z coordinate
8、s.Usually they are specified as function handles.Argument tlims specify the interval for parameter t,specifed as a two-element vector of form.The default value of tlims is from-5 to 5.2 The fplot3 Functionxt=(t)exp(-t/10).*sin(5*t);yt=(t)exp(-t/10).*cos(5*t);zt=(t)t;fplot3(xt,yt,zt,-12,12)=/10sin(5)
9、=/10(5)=,t-12,12Example 6 Create Mexican-hat curve.The parametric equation of the curve is as follows:xt=(t)exp(-t/10).*sin(5*t);yt=(t)exp(-t/10).*cos(5*t);zt=(t)t;fplot3(xt,yt,zt,-12,12,r-.)For example,plot a red dash-dot Mexican-hat curve.Line style,marker,and color,specified as a character vector or string containing symbols.The symbols can appear in any order.
