# \`cond\` and \`condskeel\`
**URL:** https://discourse.julialang.org/t/cond-and-condskeel/89328
**Category:** General Usage
**Created:** [October 26, 2022, 8:00pm UTC](https://discourse.julialang.org/t/cond-and-condskeel/89328 "2022-10-26T20:00:18Z")
**Posts on this page:** 2
**Page:** 1
### Author:  [@nchisholm](https://discourse.julialang.org/u/nchisholm)
#### Post date: [October 26, 2022, 8:00pm UTC](https://discourse.julialang.org/t/cond-and-condskeel/89328/1 "2022-10-26T20:00:18Z")
I am wondering about the usage of `cond` versus `condskeel`. I am familiar with the condition number, but not as much with the Skeel condition number. I have found that the two functions generally produce numbers of the same order of magnitude given a matrix, although `condskeel` is significantly faster. However, I am not sure if `condskeel` is intended to provide a cheaper estimate of the condition number. Moreover, `condskeel` optionally takes a vector, though I am not sure how the interpretation of `condskeel` changes when this vector is provided.
If anyone could point me to a resource on the Skeel condition number as defined in Julia, I would be grateful. Googling seems to have turned up little useful information for me.
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### Author:  [@Oscar\_Smith](https://discourse.julialang.org/u/Oscar_Smith)
#### Post date: [October 26, 2022, 8:28pm UTC](https://discourse.julialang.org/t/cond-and-condskeel/89328/2 "2022-10-26T20:28:00Z")
[numerical linear algebra - Skeel's condition number vs. classical condition number - Mathematics Stack Exchange](https://math.stackexchange.com/questions/3432308/skeels-condition-number-vs-classical-condition-number) has pretty good info here.