The Gravity Window controls the positions of measuring points and their observed values. This window was changed significantly in v2.1 compared to older versions.
V2.1 Window description:
When the window first opens, a default set of points is included. In many cases you are likely to immediately overwrite these values either by importing a text file, opening an existing GravMag data file, or typing in values you desire. You can change the number of points manually by adding points (Add... button in upper right) or deleting points (Delete button). When you add points you will get a dialog that will ask for the number of points and the limits in x and z for the new points. The coordinates of the new points will be evenly spaced between the starting and final values of x and z. To delete points, you select the points to remove (shift-click, command-click (Mac, right click Windows), shift-drag all should work) and then click the "Delete" button.
The Add to Calculated field is available to adjust for baseline differences between observations and calculated values. This can be set manually or by pressing the Use Mean Offset button, which will insert the mean offset between observed and calculated values into this field. Note that it does not automatically update.
The spreadsheet of values comprises most of the window. Listed are the horizontal (X) and vertical (Z) positions of the measurement points, their observed value, their uncertainty (if that option is chosen in the Preferences Window), and their calculated value. Clicking on this area and then clicking on the value to be changed will allow you to edit that value. Tabs will move you forward through the list; shift-tab will move backwards. Arrow keys will move you up and down if desired. Values and the Section Window are changed when the cell being edited becomes inactive (by selecting another cell or another window). Clicking on the header at the top of a column will sort the fits by values in that column. Column widths can be resized by clicking on the dividers between headers.
The RMS Misfit at the top of the window is the root mean square of the differences between observed and calculated values and is updated when calculated or observed values are changed.
You can save current model values as observations using the Paste Model Values command from the Edit Menu. You will be prompted if this would overwrite any existing measurements. The values in the table can be copied as tab-delimited text using the Copy Data command in the Edit Menu. If lines are selected, the Copy command in the Edit menu will copy only those lines. The data can be printed using the Print command and saved to a text file using the Save Gravity Data command from the File Menu. Files saved in this manner can be reopened using the Open Data File command from the File menu when the Gravity Data Window is frontmost.
You can read in data in a simple text file using the Import Delimited Text... command in the File menu. Files can have header lines that will be ignored (Lines to skip) and the X, Z, and observed gravity values can be in any columns. X and gravity values must be present. Columns are delimited by a single unique character (typically a comma or a tab). You are first prompted for the data file and then you enter the positions of the different data columns and the kind of delimiter to use through the screen seen above.
So a file like that below could be used if the lines to skip was set to 1, the delimter to ",", and the X was column 1, Z column 2, and data column 3:
Distance, Height, Measurement (mgal)
12.0,0.0,1.23
14.0,0.0,2.33
18.0,0.0,-1.22
Adding points is controlled from the Add... button, which brings up a small dialog:
Points will be inserted at even intervals from the lefthand X and Z values to the righthand values.
V2.0 and older differences
The Number of Measurements is controlled at upper right. New measurement positions are added to the end of the list and are evenly spaced. To get all the measurements evenly spaced, first change the number of measurements to 1, tab out of the edit field (or click elsewhere in the window) and then change the number of measurements to the desired value. Lowering the number of measurements will delete from the end of the list.
Other features remain as described above for v2.1 and above, though the Import Delimited Text command was added in v 1.0.14 and looked like this: