Collect Coefficients of Powers of Default Variable

Collect the coefficients of a symbolic expression.

syms x coeffs = collect((exp(x) + x)*(x + 2))

coeffs = x ^ 2 +（exp（x）+ 2）* x + 2 * exp（x）

因为您没有指定变量，收藏uses the default variable defined bysymvar. For this expression, the default variable isx.

symvar((exp(x) + x)*(x + 2), 1)

答= x

Collect Coefficients of Powers of a Particular Variable

收集系数of a particular variable by specifying the variable as the second argument to收藏.

收集系数of an expression in powers ofx, and then in powers ofy.

syms x y coeffs_x = collect（x ^ 2 * y + y * x  -  x ^ 2  -  2 * x，x）coeffs_y = collect（x ^ 2 * y + y * x  -  x ^ 2  -  2 * x，y）

coeffs_x = (y - 1)*x^2 + (y - 2)*x coeffs_y = (x^2 + x)*y - x^2 - 2*x

收集系数in powers of bothx和yby specifying the second argument as a vector of variables.

syms a b coeffs_xy = collect(a^2*x*y + a*b*x^2 + a*x*y + x^2, [x y])

coeffs_xy = (a*b + 1)*x^2 + (a^2 + a)*x*y

Collect Coefficients in Terms ofi和PI.

收集系数of an expression in terms ofi, and then in terms ofPI..

syms x y coeffs_i = collect(2*x*i - 3*i*y, i) coeffs_pi = collect(x*pi*(pi - y) + x*(pi + i) + 3*pi*y, pi)

coeffs_i = (2*x - 3*y)*1i coeffs_pi = x*pi^2 + (x + 3*y - x*y)*pi + x*1i

收集符号表达式和函数的系数

收集系数of expressions and functions by specifying the second argument as an expression or function. Collect coefficients of multiple expressions or functions by using vector input.

Expandsin(x + 3*y)和收藏coefficients ofCOS.(y)，然后是两者sin(x)和sin(y).

syms x y f = expand(sin(x + 3*y)); coeffs_cosy = collect(f, cos(y))

coeffs_cosy = 4*sin(x)*cos(y)^3 + 4*cos(x)*sin(y)*cos(y)^2 + (-3*sin(x))*cos(y) - cos(x)*sin(y)

coeffs_sinxsiny = collect(f, [sin(x) sin(y)])

coeffs_sinxsiny =（4 * cos（y）^ 3  -  3 * cos（y））* sin（x）+（4 * cos（x）* cos（y）^ 2  -  cos（x））* sin（y）

收集系数of the symbolic functionY（x）in a symbolic expression.

syms y(x) f = y^2*x + y*x^2 + y*sin(x) + x*y; coeffs_y = collect(f, y)

coeffs_y（x）= x * y（x）^ 2 +（x + sin（x）+ x ^ 2）* y（x）

Collect Coefficients for Each Element of Matrix

Call收藏在矩阵上。收藏acts element-wise on the matrix.

syms x y collect([(x + 1)*(y + 1), x^2 + x*(x -y); 2*x*y - x, x*y + x/y], x)

答= [ (y + 1)*x + y + 1, 2*x^2 - y*x] [ (2*y - 1)*x, (y + 1/y)*x]

Collect Coefficients of Function Calls

通过将函数名称指定为第二个参数来收集对特定功能的调用系数。通过将多个函数指定为字符向量的小区阵列来收集多个功能的函数调用的系数。

收集调用的系数sin功能在F, whereFcontains multiple calls to different functions.

syms a b c d e f x F = a*sin(2*x) + b*sin(2*x) + c*cos(x) + d*cos(x) + e*sin(3*x) +f*sin(3*x); collect(F, 'sin')

答= (a + b)*sin(2*x) + (e + f)*sin(3*x) + c*cos(x) + d*cos(x)

收集系数of calls to both thesin和COS.functions inF.

收集(F,{‘因为’‘罪恶’})

答= (c + d)*cos(x) + (a + b)*sin(2*x) + (e + f)*sin(3*x)