在matlab中,我们使用meshgrid
而不是双重for循环来提高速度,尤其是当迭代次数很多时。
在我的应用程序中,我使用meshgrid
来查找矩阵的临界点。
syms x
a=0.1:5
b=0.1:5
[A,B]=meshgrid(a,b)
y=A*x^2+B*x+B
y_deriv=diff(y,x)
solution=solve(y_deriv==0,x)
然而,它给了我
Warning: 25 equations in 1 variables.
> In C:\Program Files\MATLAB\R2013b\toolbox\symbolic\symbolic\symengine.p>symengine at 56
In mupadengine.mupadengine>mupadengine.evalin at 97
In mupadengine.mupadengine>mupadengine.feval at 150
In solve at 170
Warning: Explicit solution could not be found.
> In solve at 179
solution =
[ empty sym ]
我打算做的是:
solve(y_deriv(1)==0,x)
和
solve(y_deriv(2)==0,x)
......等等。
我可以循环播放,但我不想这样做。在matlab中是否有任何逐元素的解决操作?
更新
我认为y_deriv
给了我:
[ x/5 + 1/10, (11*x)/5 + 1/10, (21*x)/5 + 1/10, (31*x)/5 + 1/10, (41*x)/5 + 1/10]
[ x/5 + 11/10, (11*x)/5 + 11/10, (21*x)/5 + 11/10, (31*x)/5 + 11/10, (41*x)/5 + 11/10]
[ x/5 + 21/10, (11*x)/5 + 21/10, (21*x)/5 + 21/10, (31*x)/5 + 21/10, (41*x)/5 + 21/10]
[ x/5 + 31/10, (11*x)/5 + 31/10, (21*x)/5 + 31/10, (31*x)/5 + 31/10, (41*x)/5 + 31/10]
[ x/5 + 41/10, (11*x)/5 + 41/10, (21*x)/5 + 41/10, (31*x)/5 + 41/10, (41*x)/5 + 41/10]
我想要的是解决矩阵中所有元素的x/5+1/10==0
,x/5+11/10==0
,x/5+21/10==0
,...等等。