矩陣計算習題及答案

1、1、選擇題1) 下列變量中A是合法的。A. Char_l, i, j *y, C. Xy, al234 D. end, lbcd2) 下列 C是合法的常量。A. 3el0B. le500 C. D. 10-23) x=uint8,則x所占的字節(jié)是D 個。A. 1B. 2C. 4D. 84) 已知x=0： 10,則x有 B 個元素。A. 9B. 10C. 11D. 125) 產(chǎn)生對角線元素全為1其余為0的2X3矩陣的命令是_C ；A. Ones (2, 3) B Ones (3, 2) C. Eye (2, 3) D. Eye (3, 2)Q 2 3、6) a= 4 5 6 則 a (:, en

2、d)是指 C 。 rot90 diag、triu 和 tidl 進行操作。并9z 求其轉置、秩、逆矩陣、矩陣的行列式值及三次幕。 a=reshape(1:9,3,3); % by wl 3=3*a =1234 5 67 8 9 a=reshape(1:9,3,3); % by wl a=a* %by wl123456 fliplr(a) % by wl ans =321654987 rot90(a) %by wl ans =369258147 diag(a) %by wl789a triu(a) %by wl a % by w(ans =123056009 tril(a) %by wlans

3、二1 472 583 69rank(a) %by wl ans =2ans =100450789inv(a) %by wlWarning: Matrix is close to singular or badly scaledResults may be inaccurate. RCOND = 1.541976e-018.ans =1 0e*016 a=1 3;5 8; % by wl a* %by wl det(a) %by wlans =6.6613e-016 a304504 0.9007 -0.45040 9007 -1 8014 0 9007-0.4504 0.9007 -0.4504

4、ans =468576684106213051548166620342412ans =4685766841062130516481656203424122X 3x2 + x3 +2x4 =88. 解線性方程組X + 3x2 +x4 =6A, _七 +兀3 +8 =77x( + 3x2 - 2x3 + 2x4 = 5 A=2 -3 1 2;1 3 0 1;1 -1 1 8;7 1 -2 2 %by wlA 二2-31213011-11871-22 b=8;6;7;5 % by wl8675 x=inv(Afb %by wl2.53531.20336.8299-0.14529. 輸入字符串變量a為

5、hello將其每個字符后移4個，如5變?yōu)槿缓笤?逆序存入變量b。 a=hello： % by wl b=char(fliplr(double(a)+4) % by wlb =sppil10計算函數(shù)/(/) = 10e2f-sin(4f),其中t范圍為0到20,步長為,g (t)為f (t) 大于0的部分，計算g (t)的值。 t =0:0.2:20; %by wl f =10*exp(2*t)-sin(4*t) %by wl1.0e+018*Columns 1 through 60.0000 0.0000 0.0000Columns 7 through 120.0000 0.0000 0.00

6、00Columns 13 through 180.0000 0.0000 0.00000.00000.00000.00000.00000.00000.00000.00000.00000.0000Columns 19 through 240.0000 0.0000 0.0000 0.0000 0.0000 0.0000Columns 25 through 300.0000 0.0000 0.0000Columns 31 through 360.0000 0.0000 0.0000Columns 37 through 420.0000 0.0000 0.0000Columns 43 through

7、 480.0000 0.0000 0.0000Columns 49 through 540.00000.00000.00000.00000.00000.00000.00000.00000.00000.00000.00000.00000.0000 0.0000 0.0000 0.0000 0.0000 0.0000Columns 55 through 600.0000 0.0000 0.0000Columns 61 through 660.0000 0.0000 0.0000Columns 67 through 720.0000 0.0000 0.00000.00000.00000.00000.

8、00000.00000.00000.00000.00000.0000Columns 73 through 780.0000 0.0000 0.00010.0001 0.0002 0.0002Columns 79 through 840.0004 0.0005 0.0008 0.0012 0.0018 0.0026Columns 85 through 900.0039 0.0058 0.00870.01300.01940.0289Columns 91 through 960.04310.0643 0.09590.14310.21350.3186Columns 97 through 1010.47

9、52 0.7090 1.05771.57782.3539f1=f(f=0) %by wlf1 =1.0e+018*Columns 1 through 60.0000 0.0000 0.00000.00000.00000.0000Columns 7 through 120.0000 0.0000 0.0000Columns 13 through 180.0000 0.0000 0.0000Columns 19 through 240.0000 0.0000 0.0000Columns 25 through 300.0000 0.0000 0.0000Columns 31 through 360.

10、00000.00000.00000.00000.00000.00000.00000.00000.00000.00000.00000.00000.0000 0.0000 0.0000 0.0000 0.0000 0.0000Columns 37 through 420.0000 0.0000 0.0000Columns 43 through 480.0000 0.0000 0.0000Columns 49 through 540.0000 0.0000 0.0000Columns 55 through 600.0000 0.0000 0.0000Columns 61 through 660.00

11、00 0.0000 0.00000.00000.00000.00000.00000.00000.00000.00000.00000.00000.00000.00000.00000.00000.00000.0000Columns 67 through 72，使用數(shù)組信息獲取函數(shù)求其行列數(shù)、元素個數(shù)，是否為稀疏0.0000 0.0000 0.0000Columns 73 through 780.0000 0.0000 0.0001Columns 79 through 840.0004 0.0005 0.0008Columns 85 through 900.0039 0.0058 0.0087Columns 91 through 960.04310.0643 0.0959Columns 97 through 1010.4752 0.70901.057712 3、11.矩陣 a= 4 5 6J 8 9；0.00000.00000.00000.00010.00020.00020.00120.00180.00260.01300