Unable to perform assignment because value of type 'sym' is not convertible to 'double'. 出错 zd67 (第 29 行) x(1:3, i) = x(1:3, i-1) + x(4:6, i-1)*dt + 0.5*a*dt^2; 原因: 错误使用 symengine Unable to convert expression containing symbolic variables into double array. Apply 'subs' function first to substitute values for variables.
时间: 2024-03-03 21:51:59 浏览: 66
这个错误是因为你在进行符号计算时,尚未对其中的符号变量进行数值替换,导致无法将其转换为实数类型的数组。你需要使用Matlab中的subs函数先对其中的符号变量进行替换,才能将其转换为实数类型的数组。你可以先将符号变量进行替换,然后再进行数组赋值操作。例如,可以使用以下代码进行替换:
```
x_subs = subs(x, [a, dt], [a_value, dt_value]);
```
其中,a_value和dt_value分别为你所需要替换的a和dt的值。然后再将x_subs赋值给x即可。
相关问题
Unable to perform assignment because the size of the left side is 1-by-73216 and the size of the right side is 1-by-91648.
这个错误提示通常意味着你正在尝试将一个大小为1-by-91648的数组赋值给一个大小为1-by-73216的数组,或者反过来。请确保你的赋值操作的左右两侧的数组大小相同,或者使用类似于reshape或resize的函数来调整数组大小以匹配。你可以提供更多上下文和代码细节,这样我才能更好地帮助你解决问题。
Unable to perform assignment because the left and right sides have a different number of elements.
This error typically occurs when you try to assign values to variables or elements in a list or array, but the number of values on the left side of the assignment operator does not match the number of values on the right side.
For example, if you have a list of three elements and you try to assign four values to it like this:
my_list = [1, 2, 3]
my_list[0:3] = [4, 5, 6, 7]
You will get the error message because the number of values on the right side (4) does not match the number of elements on the left side (3).
To fix this error, make sure that the number of values on the left and right sides of the assignment operator match. If necessary, you may need to add or remove elements from the list or array before assigning new values to it.