今天小编为大家带来matlab三维绘图
01
本期主题介绍
Thetopicofthisissue
如果您了解过Matlab，
您肯定知道Matlab不只是计算！
Matlab还有一个强大的绘图功能！
本期话题将对matlab的三维图进行介绍。
请感兴趣的朋友和小编开启
学习Matlab的三维绘图之旅吧！
IfyouknowMatlab,
YoumustknowthatMatlabismorethanjustcomputing!
Matlabalsohasapowerfuldrawingfunction!
Thetopicofthisissuewillintroducethethree-dimensionaldrawingofmatlab.
Pleaseopenitwithinterestedfriendsandeditors
Learnthejourneyoftwo-dimensionaldrawinginMatlab
02
Matlab三维绘图
Matlab3Ddrawing
1.用plot绘制三维图形
Useplottodrawthree-dimensionalgraphics
x=1:5;
y=6:10;
z=x+y;
z2=exp(x+y);
[x3,y3]=meshgrid(x,y);
z3=x3+y3;
plot3(x,y,z);
plot3(x,y,z2);
plot3(x3,y3,z3);
%mesh可以绘制一段区间的曲面，调用格式mesg(x,y,z)
%注意：在使用函数前，先对xy平面建立网格坐标：[x,y]=meshgrid(x,y)
%其中meshgrid为二维三维网格
meshcandrawasectionofcurvedsurface,calltheformatmesg(x,y,z)
Note:Beforeusingthefunction,creategridcoordinatesonthexyplane:[x,y]=meshgrid(x,y)
Wheremeshgridisatwo-dimension althree-dimensionalgrid
2.绘制螺旋图
Drawaspiralgraph
t=0:pi/60:10*pi;
x=sin(t);
y=cos(t);
plot3(x,y,t,'*-b');
3.三维网格图
Three-dimensionalgridmap
mesh函数用于绘制三维网格图，其调用语法如下。
(1)mesh(x,y,z)：绘制三维网格图，x、y、z分别表示三维网格图形在x轴、y轴和z轴的坐标，图形的颜色由矩阵z决定。mesh(Z)：绘制三维网格图，分别以矩阵Z的列下标、行下标作为三维网格图的x轴、y轴的坐标。
注意事项：在使用函数前，需要先在xy平面建立网格坐标：[x,y]=meshgrid(x,y)，然后再利用新的x,y计算网格上对应z的点，从而得到构建曲面所需的点，最后再使用mesh绘制整个图。
Themeshfunctionisusedtodrawathree-dimensionalgridgraph,anditscallingsyntaxisasfollows.
(1)mesh(x,y,z):drawathree-dimensionalgridgraph,x,y,zrepresentthecoordinatesofthethree-dimensionalgridgraphonthex-axis,y-axisandz-axis,respectively.Thecolorofthegraphisdeterminedbythematrixz.mesh(Z):Drawathree-dimensionalgridgraph,andusethecolumnsubscriptsandrowsubscriptsofmatrixZasthecoordinatesofthex-axisandy-axisofthethree-dimensionalgridgraph.
Note:Beforeusingthefunction,youneedtoestablishthegridcoordinatesinthexyplane:[x,y]=meshgrid(x,y),andthenusethenewx,ytocalculatethepointcorrespondingtozonthegridtogetConstructthepointsneededforthesurface,andfinallyusethemeshtodrawtheentiregraph.
x=-8:8;
y=-8:8;
[X,Y]=meshgrid(x,y);
Z=(X.^2/4^2-Y.^2/5^2);
meshz(X,Y,Z)
4.绘制柱状图
Drawahistogram
bar3(x,y,z);
bar3(z3);
bar3(z3,'grouped')
bar3(z3,'stacked')
bar3(z3,0.3)
5.绘制直方图
Drawahistogram
%X=randn返回一个从标准正态分布中得到的随机标量。
%X=randn(n)返回由正态分布的随机数组成的n×n矩阵。
%X=randn(sz1,...,szN)返回由随机数组成的sz1×...×szN数组，其中sz1,...,szN指示每个维度的大小。例如：randn(3,4)返回一个3×4的矩阵。
%histogram为绘制直方图
%X=randnreturnsarandomscalarobtainedfromthestandardnormaldistribution.
%X=randn(n)returnsann×nmatrixcomposedofnormallydistributedrandomnumbers.
%X=randn(sz1,...,szN)returnsansz1×...×szNarraycomposedofrandomnumbers,wheresz1,...,szNindicatethesizeofeachdimension.Forexample:randn(3,4)returnsa3×4matrix.
%histogramistodrawahistogram
x4=randn(100,1);
y4=randn(100,1);
histogram2(x4,y4);
6.绘制饼图
Drawapiechart
pie3(z3)
7.绘制“火柴杆图”
Drawa"matchstickmap"
%火柴杆数
%Matchsticks
stem3(x3,y3,z3)
t=-10:0.1:10;
xt=t;
yt=sin(t);
zt=exp(t);
stem3(xt,yt,zt,'filled');
8.空间曲面绘图
Spacesurfacedrawing
%suf空间曲面绘图
%surf(x,y,z)画出数据点x,y,z表示的曲面
%画出z=(x+y)^2
%sufspacesurfacedrawing
%surf(x,y,z)drawsthesurfacerepresentedbydatapointsx,y,z
%Drawoutz=(x+y)^2
x=-2:0.1:4;
y=1:0.2:8;
[x,y]=meshgrid(x,y);
z=(x+y).^3;
surf(x,y,z)
shaingflat
9.subplot的使用，以及shading自由设置图形表面的颜色
Theuseofsubplotandshadingfreelysetthecolorofthegraphicsurface
%shaingflat使用同一种颜色配色
%shadinginterp插值处理方式配色
%shaingflatusesthesamecolor
%shadinginterpcolormatching
figure
subplot(1,3,1)
sphere(16)
axisequal
title('FacetedShading(Default)')
subplot(1,3,2)
sphere(16)
shadingflat
axisequal
title('FlatShading')
subplot(1,3,3)
sphere(16)
shadinginterp
axisequal
title('iInterpolatedShading')
10.绘制极坐标图
Drawpolarcoordinates
a=10
k=2
theta=0:pi/50:2*pi;
r=a*sin(k*theta);
h=polar(theta,r)
set(h,'color',[1,0,0],'LineWidth',2)
今天的分享就到这里了。