springzhao 发表于 2018-9-28 12:18

请教达人,为什么matlab中的模态矩阵不是对角阵

理论上应该是对角阵,算下来非对角位置有小的值,不知什么原因?请教一下达人

mxlzhenzhu 发表于 2018-9-28 20:07

笨蛋。那么小,还不是0?

fatherchen 发表于 2018-10-5 15:19

应该是因为matlab电脑计算进制计算的,这在进制转换中会产生一些误差吧,然后你用inv这个命令也会产生一些误差,但是通常可以忽略

springzhao 发表于 2018-10-10 10:51

fatherchen 发表于 2018-10-5 15:19
应该是因为matlab电脑计算进制计算的,这在进制转换中会产生一些误差吧,然后你用inv这个命令也会产生一些 ...

应该是这个问题,于是我采用了符号来推导表达式,但是想看工作空间中符号矩阵的元素表达式,却只能看到这个data:image/png;base64,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
页: [1]
查看完整版本: 请教达人,为什么matlab中的模态矩阵不是对角阵