Plot from “Data”

? MATLAB does not understand functions
????(??) = sin(2????)
? Strategies

1. Generate the numeric values of a function over a specific range.
2. Display the data “points” in a graphical way.

plot()

? plot(x,y) plots each vector pairs (x,y)
? plot(y) plots each vector pairs (x,y),where x=[1…n], n=length(y)
? Example:
??plot(cos(0:pi/20:2*pi));

hold on/off

? Use hold on to have both plots in one figure.

在一張圖片上繪制兩個圖

Plot Style

? plot(x,y,'str') plots each vector pairs (x,y) using the format defined in str (check linespec)

繪圖風(fēng)格

legend()

? Add legend to graph
??legend('L1',...)
? Position adjustment

帶label的函數(shù)圖形

label的實現(xiàn)語法

title() and label()

? title()
? xlabel()
? ylabel()
? zlabel()

屏幕截圖(69).png

x,y軸的名稱及圖片標題

text() and annotation()

? Text with mathematical expression using LaTex

Exercise

? Plot ?? as a black line and ?? as a series of red circles for the range t = 1 to 2 in one figure
???? = and ?? = sin(2????)
? Label each axis, and add title and legend

Figure Adjustment

? Several properties:

? Font
? Font size
? Line width
? Axis limit
? Tick position
? Tick label

Graphical Objects

? A figure is composed of many objects

屏幕截圖(81).png

Figure Properties

屏幕截圖(82).png

Modifying Properties of An Object

? Strategy:

1. Identify the “handle” of an object
2. Fetch or modify the object’s properties

? For example, to change the limits of the x-axis:

1. Find the handle of the x-axis
2. Modify the limits

1. Identifying the Handle of An Object

? Upon creation:
??h = plot(x,y);

? Utility functions:

Fetching or Modifying Properties

? To fetch properties, use
??get( )
? To modify properties, use
??set( )

Getting Object Properties

? Getting properties of a graphical object: get( )

Setting Axes Limits