<p>I am trying to gain experience in <a href="https://www.l3harrisgeospatial.com/Software-Technology/IDL" rel="nofollow noreferrer">IDL</a> in order to do basic image data reduction techniques like stacking and aperture photometry, so I decided to purchase an IDL license, however, the license is linked with ENVI but I am not sure what that is? I know IDL is very popular in the astronomy community, but is ENVI needed?</p>

CC BY-SA 4.0
2022-03-23T08:06:33.193Z
IDL *used* to be very popular, but has mostly been replaced by Python. You would almost certainly be better off using that (in addition to the fact that it’s free).
Peter Erwin
CC BY-SA 4.0
2022-03-23T08:08:35.537Z
@PeterErwin Oh, I am already very familiar with python. So if I already know python, then there is no need to learn IDL?
Robin
CC BY-SA 4.0
2022-03-23T08:13:56.600Z
Unless you have some very unusual/specific use case for which only an IDL package exists, then, yes, there’s no need to learn IDL. (I used it all the time in the 90s and early 2000s, but basically haven’t used it at all in the last ten years.)
Peter Erwin
CC BY-SA 4.0
2022-03-23T08:26:53.000Z
Here idl was dropped in favour of python basically 5 to 10 years ago. Only legacy code still uses it, and it is getting less quickly. Python has the much easier to use tools, documentation and saves the license hassle
planetmaker
CC BY-SA 4.0
2022-03-23T09:06:55.250Z
There is also GDL https://en.wikipedia.org/wiki/GNU_Data_Language which I have used to keep some old IDL scripts running without needing a license. Last time i used it, it wasn't a complete replacement but got most of the way there.
Rob
CC BY-SA 4.0
2022-03-23T15:14:38.073Z
FORTRAN and IDL are not dead, but most of their users seem to be older. Python has way more community-developed packages, but that can also be a liability because you have to stay updated. In IDL one of the most important "packages" for astronomy is AUL: https://idlastro.gsfc.nasa.gov/
giardia
CC BY-SA 4.0
2022-03-27T15:47:12.783Z
ENVI is mostly used by Earth Science folks (and some medical folks).  Most astronomers who still use IDL do not bother with it.  They make use of the gsfc package mentioned by giarda.
eshaya
<data-analysis><software><image-processing>
Do I need ENVI if I want to just learn IDL?
Robin
# Do I need ENVI if I want to just learn IDL?

(Asked by: username_0 on 2022-03-23)

I am trying to gain experience in [IDL](https://www.l3harrisgeospatial.com/Software-Technology/IDL) in order to do basic image data reduction techniques like stacking and aperture photometry, so I decided to purchase an IDL license, however, the license is linked with ENVI but I am not sure what that is? I know IDL is very popular in the astronomy community, but is ENVI needed?

**Tags:** data-analysis, software, image-processing

> **Comments:**
> **username_1**: IDL *used* to be very popular, but has mostly been replaced by Python. You would almost certainly be better off using that (in addition to the fact that it’s free).  
> **username_0**: @PeterErwin Oh, I am already very familiar with python. So if I already know python, then there is no need to learn IDL?  
> **username_1**: Unless you have some very unusual/specific use case for which only an IDL package exists, then, yes, there’s no need to learn IDL. (I used it all the time in the 90s and early 2000s, but basically haven’t used it at all in the last ten years.)  
> **username_2**: Here idl was dropped in favour of python basically 5 to 10 years ago. Only legacy code still uses it, and it is getting less quickly. Python has the much easier to use tools, documentation and saves the license hassle  
> **username_3**: There is also GDL https://en.wikipedia.org/wiki/GNU_Data_Language which I have used to keep some old IDL scripts running without needing a license. Last time i used it, it wasn't a complete replacement but got most of the way there.  
> **username_4**: FORTRAN and IDL are not dead, but most of their users seem to be older. Python has way more community-developed packages, but that can also be a liability because you have to stay updated. In IDL one of the most important "packages" for astronomy is AUL: https://idlastro.gsfc.nasa.gov/  
> **username_5**: ENVI is mostly used by Earth Science folks (and some medical folks).  Most astronomers who still use IDL do not bother with it.  They make use of the gsfc package mentioned by giarda.  

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## 0 answers

