Using the editor
The Ephemeris Format Editor is started by pressing the 
Ephemeris Format Editor button in the toolstrip of the Ephemeris Interpolator window.
A set of ephemeris formats are stored locally in the Ephemeris Interpolator and individual formats can be added, changed or deleted using the Ephemeris Format Editor.
When a format has been edited, the changes can be updated in memory using the 
Update Ephemeris format button, or the changes to the format can be rolled back using the 
Undo button. When changes to one or more formats have been made, the user can choose to either 
Save ephemeris formats to disk for subsequent use by the Ephemeris Interpolator, or to abandon all the changes from the editing session.
In addition to the local set of formats, a core set of ephemeris formats are held online at the Ephemeris Interpolator website. When new ephemeris formats are encountered these can be included in this core set and are then available to be imported using the Ephemeris Formats Editor 
Check for ephemeris format updates button.
Click on the toolstrip buttons to jump to more information:
or see the following sections for more information
Check for ephemeris format updates
Add new ephemeris format
- Choose "(new)" in the drop-down list under "Select format to edit or (new) to add" if "(new)" is not already selected
- Enter a unique name for the new format in Format Name
- Enter a description for the format in Description. If the ephemeris is generated from a source with specific options then they can be listed here (e.g. a JPL Horizons format could list the Table Setting numbers used)
- Optionally enter remarks in Remarks. If remarks are entered they will be displayed as a tool tip in the Ephemeris Interpolator window when the mouse is moved over the Matched format area. Clicking the Matched format area will then temporarily transfer the remarks to the message area.
- Paste at least one line from the ephemeris to be added into the edit area, to be used as a "model" line. Only the first line is used during the editing process, but having more than one line can help identify the columns of data. If more than one line is entered, it is automatically separated from subsequent lines with a message advising "Only select text in first line of ephemeris".
Configuring columns
Now the columns in the model line containing the values for Year, Month, Day, Hour, Min, Sec, RA, Dec, Speed, P.A.° are configured, one at a time.
For each value:
- Select the appropriate text in the model line with either mouse, by holding the left mouse button while dragging, or using the keyboard, by holding the Shift key and using the left or right arrow keys to highlight text. Take care to highlight all the columns that could possibly contain digits, mainly affecting Speed and P.A.°. For instance P.A.° can range from 0.0 to 359.9, so a value of 17.4 in the model line should be highlighted to include a leading space, e.g. 17.4 rather than 17.4. See Zero-suppressed columns.
- Save the column configuration, either
- by mouse: click on the name of the matching value, e.g. (y)Year
- by keyboard: press the key within brackets, e.g. "y" for the (y)Year value. Note: be careful when entering d or D, m or M and s or S to use the Shift key appropriately.
- The starting point and length of the selected text is shown and, as a verification, the text that was selected is also displayed
As an example of configuring where the year value is to be found, the year is selected in the model ephemeris line:
Next, "(y)Year" is clicked (or the y key is pressed), resulting in the new configuration being displayed, (y)Year starting in column 1, 4 characters long, picking up the value 2021 from the ephemeris line and placing "yyyy" as a column heading above the model line in columns 1-4:
If a value is set by mistake and needs to be set back to "(not configured)" then de-select any selected text and click on the name of the value to be reset (or press the appropriate key indicated within brackets).
Repeat those steps for each of the values available in the ephemeris. If Speed and P.A.° are not included in the ephemeris then leave those settings as "(not configured)", the Speed and P.A.° will then be determined from the rate of change of the ephemeris positions when 
Calculate is pressed in the Ephemeris Interpolator or Pad windows.
When all configuration is done, press the Add new ephemeris format toolstrip button.
Update ephemeris format
Select an existing ephemeris format using the drop-down list under the heading "Select format to edit or (new) to add:".
The list of matches with existing formats is updated and any warnings issued if there are other formats that are a close match to the selected format.
The edit area is refreshed with the model line for the selected ephemeris format and the other data elements for the format.
Modify the configuration of any of the values for Year, Month, Day etc. as described in Configuring columns.
Modify Description and Remarks.
When changes have been made to the format an asterisk (*) appears to the left of the format name at the top left of the edit area to signify that there are unsaved changes.
Press the Update ephemeris format toolstrip button to complete the changes.
Here the MPES format has been selected, with the editor areas of interest highlighted:
Rename existing format
The user is prompted to enter a new name for the currently selected format. Enter a new name and press OK, or press Cancel to abandon renaming.
Undo changes
For the format currently being edited press the Undo changes toolstrip button to revert the format to the version last saved to disk using the Save ephemeris formats button, or when exiting the Editor, saving changes.
Delete ephemeris format
Select an existing ephemeris format using the drop-down list.
Press the Delete ephemeris format toolstrip button.
A Delete Ephemeris Type confirmation prompt will be displayed. Press Yes to delete, or press No to keep the format.
Save ephemeris formats
When any changes have been made to the collection of ephemeris formats an asterisk (*) appears to the left of the Ephemeris Format Editor window title to signify that there are unsaved changes. Press the Save ephemeris formats toolstrip button to save all the changes to disk. See 
Exit if the editor is exited before unsaved changes have been saved.
Check for ephemeris format updates
Help F1
Display this help document (online version is available via link in the About screen). Same as pressing function key F1.
Exit
Exit Ephemeris Format Editor and return to the Ephemeris Interpolator window.
If there are unsaved changes in the Editor then a prompt will be displayed "Save all changes to the ephemeris formats?". Press Yes to save and exit, No to abandon all changes and exit or press Cancel to return to the editor to continue making changes.
Understanding match scores
When a model line is entered or changed it is pattern matched against all existing formats, as well as itself, to determine a score for comparing how similar the new format is to other formats. Scoring involves comparing whether equivalent columns in two formats both contain numeric characters, spaces, alphabetic characters, decimal points, + or - signs or colons (:) .
Matching the model line to itself gives a high score and is shown as "Match score". If any of the other formats score the same, higher or have similar scores to the Match score then warnings will be displayed. This probably indicates that the same format already exists and therefore does not need to be added again, but may also indicate a problem if another format has similar structure but has different data fields in its columns. In practice this is uncommon.
The setting ShowEphFormatMatches can help determine if other formats are being matched with similar scores to the intended format, possibly leading to incorrect ephemeris values being calculated. When set to True, each time an ephemeris is matched with existing formats (i.e. when being added or replaced), a list of the scores calculated by matching the ephemeris against each existing format is displayed, with the closest match at the top of the list. Press OK to continue showing Ephemeris Format Matches when ephemerides are added or replaced, or press Cancel to change the ShowEphFormatMatches setting to False, to stop showing matches.
Example: Here an ephemeris being added can be seen to match four existing ephemeris formats to within 6 points:
Zero-suppressed columns
To maximise the likelihood of an ephemeris line matching the correct model line, if there are zero-suppressed columns of data in the model line, any blank columns can be manually edited to be numeric. This will increase the match score for ephemeris lines where there are also numerics in those columns, but will also increase match scores even when the ephemeris columns contain spaces. Most commonly this will apply to the Speed and P.A.° columns. As an example, if the model line used for a format has Speed and P.A.° as indicated below:
SSSS.SS PPPPP
20.9 9.89 339.8
then it would be an advantage to edit the model line columns for Speed to have leading numerics as below:
SSSS.SS PPPPP
20.9 0009.89 339.8
Note: It is very important to make sure that the original column positions are maintained, by replacing spaces with numerics, do not just insert numerics.
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