![topcat topcat](https://www.drawingtutorials101.com/drawing-tutorials/Cartoon-TV/Top-Cat/officer-dibble/how-to-draw-Officer-Dibble-from-Top-Cat-step-0.png)
In this case we can use the column number instead ($41 for but you can seel the column numbers in the "Views -> Column Info" menu). Sqrt ( (feh_1 - feh_ave)*(feh_1-feh_ave) + (feh_2-feh_ave)*(feh_2-feh_ave))Īnd for "ELODIE vs GBS" the operation is even trickier because the original name of the metallicity column in ELODIE is which is not valid in the TOPCAT "Expression". Sqrt ( (feh - feh_ave)*(feh-feh_ave) + (meta-feh_ave)*(meta-feh_ave))
![topcat topcat](https://d1nslcd7m2225b.cloudfront.net/Pictures/480xAny/9/5/8/1228958_top-cat.jpg)
In the case that you want to do this also for the metallicity, the operation is a little trickier because the original columns have different names depending on the catalogue. Given that writing these long expressions from scratch is quite boring, we copy them here so that you can copy+paste them: We first define the column for the "teff" average value:Īnd then we create another column and we use this teff_ave column to calculate the standard deviation:Īnd we repeat the operation to define logg_ave and logg_err in a similar way. In order to do this, we have to give a new name for the new column and intruduce a mathematical "expression" to calculate the new column content in terms of other columns (using the names of these other columns). In order to do that we visualize one of the crossmatch tables, use the right mouse button and click in "New synthetic Column". In particular, for each object, we want to calculate the mean value and standard deviation of the values of "teff" given by each catalogue. We want to add new columns to each crossmatch table so that we can do some statistics on the relevant parameters. To see all the content of a table, we select it and just click the corresponding icon. You can see that TOPCAT, when crossmatchs two tables and there are common column names in both tables, labels the new columns with "_1" and "_2" to In order to do that, we unmark the "Visible" column for all the properties that we want to hide. For instance, for the "Miles vs GBS" table, we decide to show only the more relevant columns. This can be unconfortable to visualize the table content but we can decide what columns to show using the "Views -> Column Info" menu (or just the corresponding icon).Ī new window opens with the list, and properties, of the table columns. Then we do likewise with the other two match tables.Įach crossmatch table contains a lot of columns (all the columns in both catalogues). We change "match(7,6)" (meaning "match of tables 7 and 6") to "MILES vs GBS" and click enter.
![topcat topcat](https://www.yacht.de/__image/a/4398064/alias/xl/a/b/c/1/ar/4-3/topcats-neue-einhand-rakete-k3x.jpg)
In order to do that we just select one of them and change the "Label" on the right. We could prefer to rename the crossmatch tables so that we remember better what they contain.