Summary

inaccuracy in exponential functions

Metadata

• Id: dbe640fdd2af954a3ea8effd647f88707e87badc
• Trac id: 1833
• Type: defect
• Reporter: sjain59
• Owner:
• Cc:
• Status: new
• Component: unknown
• Estimated difficulty:
• Resolution:
• Priority: minor
• Milestone: someday
• Version: 5.3.0
• Changetime: 2024-02-29 14:58:37 UTC
• Created: 2024-02-29 14:58:37 UTC
• Keywords:

Description

I wish to bring to your kind notice the following:

(sin -1e-6i), whose magnitude should be sinh, gives inaccurate answer, in comparison SCM scheme for the same expression, gives the correct C function answer. The discrepancy is related to the C functions expm1 and log1p which are needed for small x.

Another thing I noticed is the expression (sin 1e-6i) gives the error 1e-6 unbound variable, whereas in the expression (sin +1e-6i) it is correctly recognized as a number.

Thanks.