Galaxy Zoo Starburst Talk

Creating New Fields in Tools Tables

  • trouille by trouille scientist, moderator, admin

    Post by JeanTate that I'm porting to its own discussion thread.

    I tried to create a New Filter; nothing seemed to happen! I assume that the number of records in my table should decrease (my new filter should have left me only ~10%). Help!

    Posted

  • trouille by trouille scientist, moderator, admin

    A mini-tutorial on creating new fields in Quench Tools tables.

    1. Click on Data, then click on Quench, then click on Quench Sample to read in that Sample into Quench tools.

    2. Click on Tools and then click on Scatterplot.

    3. Choose Quench-1 as your data source.

    4. Plot Redshift on the x-axis and logMass on the y-axis. This shows the plot for your entire Quench sample.

    5. Click on Tools and then click on Table.

    6. Choose Quench-1 as your data source.

    7. Click Guide (under the Prompt box) to see the commands you can use.

    8.) Type:
    filter .redshift > 0.2
    #(this reduces your table to only include sources with redshifts greater than 0.2.)

    1. Click on Tools and then click on Scatterplot

    2. Choose Table-2 as your data source.
      #(this means you're choosing the table that only has sources with redshifts > 0.2)

    3. Plot Redshift on the x-axis and logMass on the y-axis.

    4. Compare your first scatter plot with this new scatter plot.

    Are they different? If yes, then you're ready to play with the New Filter prompt.

    Posted

  • robert_gagliano by robert_gagliano

    Fields and Filters not working for me...anyone else?

    Posted

  • bumishness by bumishness Zooniverse Team

    The syntax on adding fields and filters has changed a bit. Here are some examples.

    filter .redshift > 0.2
    field 'Color', .u + .g

    Replace field names as appropriate.

    Posted

  • vrooje by vrooje moderator, scientist

    Ah! The syntax has changed but the guide hasn't yet; I was stuck too. Thank you!

    Posted

  • edpaget by edpaget

    Sorry guys I forgot about the guide when I changed that. It's updated now!

    Posted

  • vrooje by vrooje moderator, scientist

    Awesome! Thanks.

    Posted

  • Peter_Dzwig by Peter_Dzwig

    Ed, is there a definitive guide to the syntax? and can we do things like subtract two sets of data one from another to generate a third?

    Posted

  • trouille by trouille scientist, moderator, admin

    If you click on 'Guide' underneath Prompt in the table within Tools, you'll pull up the Guide. If you have questions, definitely post them here. Likely it'll help us provide more needed description in that Guide.

    Posted

  • trouille by trouille scientist, moderator, admin

    Hey all, I revised the 'mini-tutorial' above to reflect the updated syntax.

    Posted

  • Peter_Dzwig by Peter_Dzwig

    Thanks

    Posted

  • JeanTate by JeanTate in response to trouille's comment.

    This is, in many ways, a very good tutorial.

    However, I think it fails, in some respects, and I think it's worth having a discussion about why.

    Consider this:

    • "If yes, then you're ready to play with the New Filter prompt. "
    • "Hey all, I revised the 'mini-tutorial' above to reflect the updated syntax. "

    If all of this is totally new to you, how would you understand "the New Filter prompt"? Especially if your English isn't very good? Would you repeat the steps outlined, a dozen times, scrutinizing everything, hoping to find this "New Filter prompt"? Would you conclude that this is one place in the mini-tutorial that was NOT updated to reflect the updated syntax?1

    Consider this:

    • "10) Choose Table-2 as your data source. #(this means you're choosing the table that only has sources with redshifts > 0.2)"

    If you've never done any coding in your life, have no idea what a "comment" is, ... what chance is there that you'll realize that the hash character is being used, here, to indicate a parenthetical comment (and is not part of the actual instruction, or 'New Field prompt')? Doubly so, because the parenthetical comment is already in parenthesis!?

    When I followed every step in the above, slavishly, I could not find any "Table-2" 😮 In my dashboard there's a Table-3 (when I used that I got what I think was intended). Does it matter that there are two different Tables?

    So, here's a suggestion: let's find a brave zooite - one with no (or very little) previous experience with data analysis, coding, etc; one whose English is OK, but nowhere near native speaker fluency; etc - and work with her, showing her how to do something like create a new field, or create (and use) a filter. Then ask her to write the mini-tutorial!

    When - a lifetime or two ago - I was a teacher, I found a particularly powerful way of helping a student develop a new skill was to ask them to teach it (this is a shorthand, of course, and of course people have different learning styles, etc, etc, etc).

    What do you think?

    1 Not to mention the title of this thread!

    Posted

  • astropixie by astropixie scientist

    i want to create a new field with log10 of halpha_flux. i think the syntax should be this, but it's not working. suggestions?

    field 'logHalpha', log(.halpha_flux, 10)

    UPDATE: no need for the parenthesis

    field 'logHalpha', log .halpha_flux, 10

    Posted