1. Yang-Ming University, Taipei, Taiwan
Graphics II

2. Colormap

3. Color Map RGB Matrix of color map Red: 0~1 Green: 0~1 Blue: 0~1 R G B
0.5 1
RGB
Red: 0~1
Green: 0~1
Blue: 0~1
Matrix of color map

4. Default cmaps help colormap Create a 20-level hot cmap gray jet hot
help colormap
gray
jet
hot
hsv ……
Create a 20-level hot cmap
hot(20)
colormap(hot(20))

5. User-Defined Color Map . . .
col1=[zeros(20,1),zeros(20,1),linspace(0,1,20)']; col2=[zeros(20,1),linspace(0,1,20)',linspace(1,0,20)']; col3=[linspace(0,1,20)',linspace(1,0,20)',zeros(20,1)]; cmap=[col1;col2;col3]; colormap(cmap); colorbar . . . . . .

6. 製作一從黑到紅，紅到黃，黃到綠的colormap，更換無尾熊 的色階為此colormap
(MATLAB會把執行結果顯示在command window上)

7. Graphics in 3-D

8. 3-D Plot 3-D line plot Syntax plot3(X1,Y1,Z1,...,Xn,Yn,Zn)
t = 0:pi/50:10*pi;
st = sin(t);
ct = cos(t);
figure; plot3(st,ct,t)
hold on
plot3(ct,st,t)
grid on
3-D line plot
Syntax
plot3(X1,Y1,Z1,...,Xn,Yn,Zn)
t = 0:pi/50:10*pi;
st = sin(t);
ct = cos(t);
figure; plot3(st,ct,t)

9. 3-D Plot by Specifying Line Style
Description -
Solid line (default) --
Dashed line :
Dotted line -.
Dash-dot line
Marker
Description o
Circle +
Plus sign *
Asterisk .
Point x
Cross s
Square d
Diamond ^
Upward-pointing triangle v
Downward-pointing triangle
>
Right-pointing triangle
<
Left-pointing triangle p
Pentagram h
Hexagram
Color
Description y
yellow m
magenta c
cyan r
red g
green b
blue

10. 3-D Plot – Specify Line Style
Syntax
plot3(X1,Y1,LineSpec1,...,Xn,Yn,LineSpecn) ('CLM': color, line, marker)
t = 0:pi/50:10*pi;
st = sin(t);
ct = cos(t);
figure; plot3(st,ct,t,'r-')

11. 3-D Plot – Change Properties of Line
plot3(...,'PropertyName',PropertyValue,...)
Line properties
Color
LineStyle
LineWidth
Marker
MarkderSize
MarkerEdgeColor
MarkerFaceColor …

12. 3-D Plot – mesh Syntax mesh(X,Y,Z) mesh(Z) [X,Y] = meshgrid(-8:.5:8);
R = sqrt(X.^2 + Y.^2) + eps;
Z = sin(R)./R;
figure; mesh(Z)

13. 3-D Plot – surf Surface plot Syntax surf(X,Y,Z) surf(X,Y,Z,C)
[X,Y] = meshgrid(1:0.5:10,1:20);
Z = sin(X) + cos(Y);
C = X.*Y;
surf(X,Y,Z)
colorbar
surf(X,Y,Z,C)
Surface plot
Syntax
surf(X,Y,Z)
surf(X,Y,Z,C)
The function plots the values in matrix Z as heights above a grid in the x-y plane defined by X and Y.

14. 3-D Sphere Plot figure; sphere % Create a 20-by-20 faces sphere

15. 3-D Sphere Plot [x,y,z] = sphere; figure; surf(x,y,z) hold on
surf(x+3,y-2,z) % centered at (3,-2,0)
surf(x,y+1,z-3) % centered at (0,1,-3)
[x,y,z] = sphere;
figure;
mesh(x,y,z)

16. 3-D Plot – patch Create one or more filled polygons Syntax
patch(X,Y,C)
patch(X,Y,Z,C)
x = [2 5; 2 5; 8 8];
y = [4 0; 8 2; 4 0];
c = [0; 1];
figure; patch(x,y,c)
colorbar

17. 3-D Plot – patch
figure;
Pl_lat = patch('Faces', data.faces_l, 'Vertices', data.vertices_l, 'FaceColor', [ ], 'EdgeColor', 'none', 'Facealpha', 0.5);
view(gca, -90,0);
light(gca, 'Style', 'infinite', 'Position', [0 1 0])
set(Pl_lat, 'FaceLighting', 'gouraud');
light(gca, 'Style', 'infinite', 'Position', [0 -1 0])
light(gca, 'Style', 'infinite', 'Position', [-1 0 0])
set(gca, 'Color', [0 0 0])

18. 在command window輸入“L = 160*membrane(1,100);” 使用“surface”畫圖 去除edgecolor
Create a matlab logo
在command window輸入“L = 160*membrane(1,100);”
使用“surface”畫圖
去除edgecolor
調整圖軸為X: [1 201], Y: [1 201], Z: [ ]
打兩道光：一為位置在[ ]顏色為[ ]的光， 另一為位置在[ ];顏色為[ ]的光
更改物體顏色為[ ]
更改背景顏色為黑色並將圖軸去除
(MATLAB會把執行結果顯示在command window上)

19. Thank you for your attention!!