信息的編程加工

信息的編程加工第課10編程繪制y=x^2的函數(shù)圖像問題分析“描點法”手工繪制步驟：第一步準備好繪圖工具；第二步繪制坐標(biāo)系的橫軸與縱軸；第三步依據(jù)要繪圖的函數(shù)表達式，

選擇幾個自變量的值算出相

應(yīng)的因變量值，得到一組坐

標(biāo)點；第四步在坐標(biāo)系上描出這幾個點，

盡量光滑地描點連線。問題分析計算機編程繪制函數(shù)圖像的過程：第一步選擇計算機程序設(shè)計語言；第二步繪制坐標(biāo)系；第三步根據(jù)函數(shù)表達式計算所要描

點的坐標(biāo)；第四步在坐標(biāo)系上描點成像。讓我們一起動手體驗編程信息編程加工的四個步驟①分析信息；②設(shè)計方法；③編寫代碼；④調(diào)試運行。②設(shè)計方法；③編寫代碼；認識代碼PrivateSubCommand1_Click()

Dimx,yAsSingle

Picture1.Scale(-10,25)-(10,-25)

Picture1.Line(-10,0)-(10,0),RGB(0,0,255)

Picture1.Line(0,25)-(0,-25),RGB(0,0,255)

Forx=-10To10Step0.0001 y=x^2

Picture1.PSet(x,y),RGB(255,0,0)

Nextx

EndSub PrivateSubCommand1_Click()

Dimx,yAsSingle

Picture1.Scale(-10,25)-(10,-25)

Picture1.Line(-10,0)-(10,0),RGB(0,0,255)

Picture1.Line(0,25)-(0,-25),RGB(0,0,255)

Forx=-10To10Step0.0001 y=x^2

Picture1.PSet(x,y),RGB(255,0,0)

Nextx

EndSub 認識代碼PrivateSubCommand1_Click()

‘確定按鈕單擊事件

Dimx,yAsSingle

Picture1.Scale(-10,25)-(10,-25)

Picture1.Line(-10,0)-(10,0),RGB(0,0,255)

Picture1.Line(0,25)-(0,-25),RGB(0,0,255)

Forx=-10To10Step0.0001 y=x^2

Picture1.PSet(x,y),RGB(255,0,0)

Nextx

EndSub

‘結(jié)束程序認識代碼PrivateSubCommand1_Click()

Dimx,yAsSingle

‘定義x,y兩個變量

Picture1.Scale(-10,25)-(10,-25)

Picture1.Line(-10,0)-(10,0),RGB(0,0,255)

Picture1.Line(0,25)-(0,-25),RGB(0,0,255)

Forx=-10To10Step0.0001 y=x^2

Picture1.PSet(x,y),RGB(255,0,0)

Nextx

EndSub 認識代碼PrivateSubCommand1_Click()

Dimx,yAsSingle

Picture1.Scale(-10,25)-(10,-25)

‘定義坐標(biāo)系

Picture1.Line(-10,0)-(10,0),RGB(0,0,255)

Picture1.Line(0,25)-(0,-25),RGB(0,0,255)

Forx=-10To10Step0.0001 y=x^2

Picture1.PSet(x,y),RGB(255,0,0)

Nextx

EndSub （-10，25）（10，-25）認識代碼PrivateSubCommand1_Click()

Dimx,yAsSingle

Picture1.Scale(-10,25)-(10,-25)

Picture1.Line(-10,0)-(10,0),RGB(0,0,255)‘畫橫坐標(biāo)軸，顏色為藍色

Picture1.Line(0,25)-(0,-25),RGB(0,0,255)

Forx=-10To10Step0.0001 y=x^2

Picture1.PSet(x,y),RGB(255,0,0)

Nextx

EndSub （-10，0）（10，0）認識代碼PrivateSubCommand1_Click()

Dimx,yAsSingle

Picture1.Scale(-10,25)-(10,-25)

Picture1.Line(-10,0)-(10,0),RGB(0,0,255)

Picture1.Line(0,25)-(0,-25),RGB(0,0,255)‘畫縱坐標(biāo)軸，顏色為藍色

Forx=-10To10Step0.0001 y=x^2

Picture1.PSet(x,y),RGB(255,0,0)

Nextx

EndSub （0，25）（0，-25）認識代碼PrivateSubCommand1_Click()

Dimx,yAsSingle

Picture1.Scale(-10,25)-(10,-25)

Picture1.Line(-10,0)-(10,0),RGB(0,0,255)

Picture1.Line(0,25)-(0,-25),RGB(0,0,255)

Forx=-10To10Step0.0001 y=x^2 ‘用循環(huán)語句描點畫函數(shù)圖像

Picture1.PSet(x,y),RGB(255,0,0)

Nextx

EndSub 認識代碼PrivateSubCommand1_Click()

Dimx,yAsSingle

Picture1.Scale(-10,25)-(10,-25)

Picture1.Line(-10,0)-(10,0),RGB(0,0,255)

Picture1.Line(0,25)-(0,-25),RGB(0,0,255)

Forx=-10To10Step0.0001

‘x值從-10變化到10，每次增量為0.0001y=x^2 ‘計算y值

Picture1.PSet(x,y),RGB(255,0,0)‘用紅色描出坐標(biāo)為（x,y）的點

Nextx