Geeky Problem That Needs a Solution.

[slacker22]

So, for various reasons I'm not going to get into right now, I need a 3-D starmap. I have (or can get) the astronomical data that lists the spectral type of stars and their XYZ coordinates. What I need to do is quasi-randomly select about 150 stars from that list within about a hundred light years of Earth, skewed heavily towards F, G, and K

Comments

[themissingy]

You can use the rand() function in excel (I am assuming that the data you can get is in comma-delimited format or other Excel-importable) to generate a column of random numbers and then, say, sort by the randomized column and select the top 150.
That should fake randomness well enough.

[slacker22]

That could work, my problem is that I want to selectively weight it to certain values in a category, so, say, 120 out of 150 of those results are of those three types, and only 30 are outside of those three values.

And yeah, it's an excel sheet.

[themissingy]

Create a column for "Type", use if(condition, then, else) to assign "1" or "2" to this column depending on what your original type was. For example, =IF(OR(A1=123,A1=456,A1=789),1,2).
Then sort by both, "Type" and "Random"; pick out 120 off the top of the Type=1; pick out remaining 30 off the top of Type=2; stick them in a different spreadsheet.

[slacker22]

...I'm going to have Irina help me on that, but I think I get what you're saying. Yes.

(I'm just not much for excel, it's the only Microsoft Office product that continues to baffle me years later)

[striknein]

You couldn't have run out of passwords already.

[slacker22]

lol, no, I have a few hundred more to go.