subarray, IF_index Plot time sampling for each telescope of an observation. EXAMPLES -------- 1. Displaying telescope sampling on an interactive device. 0>tplot Graphics device/type (? to see list, default /NULL): /xw Move the cursor into the plot window and press 'H' for help All but the first line of the above is output from tplot. 2. Displaying telescope sampling of all sub-arrays, on a hard-copy device. 0>dev /ps 0>tplot Page 01: Subarray 1 Page 02: Subarray 2 0> One page was plotted per sub-array to a postscript file. 3. Displaying telescope sampling of a single selected sub-array, on a hard-copy device. 0>dev /ps 0>tplot 3 Page 01: Subarray 3 0> A single page was plotted to a postscript file, showing telescope sampling in sub-array 3. 4. Starting the plot from sub-array 1 of IF 2. 0>tplot 1, 2 Move the cursor into the plot window and press 'H' for help ARGUMENTS --------- subarray - Default="" which selects all sub-arrays, starting from 1. To start plotting at a specific sub-array, provide its number here. The first sub-array is number 1. If the output device is a non-interactive (eg. hard-copy) device then only this sub-array will be plotted. IF_index - Default=The index of the first sampled IF. The index of the IF to plot first. CONTEXT ------- tplot plots the sampling of all telescopes, using one page per sub-array and IF. Each telescope is assigned a line parallel to the time axis of the plot. At the time-stamp of each integration, each telescope whose visibilities have not been completely deleted is shown as a dot. In general, each telescope is sampled on a number of baselines per integration. If the visibilities to all those baselines are not flagged, then the point is plotted in green. If some are flagged but at least one is not flagged then orange is used, and if all visibilities are flagged then the point is plotted either in red or blue depending on whether the flagging is dominated by visibility flags or by selfcal correction flags. Note that what the visibilities that go into determining the flag status of the plotted points, are those selected with the 'select' command, rather than all visibilities in the observation. INTERACTIVE MODE ---------------- If the device that you are plotting on possesses a cursor, then tplot goes into an interactive mode. In this mode, move the cursor into the plot area and press one of the following keys: H - (Help) Briefly list all keyboard options. X - Quit the tplot session, and return to the difmap prompt. L - Re-display the plot. N - Display the sampling of the next sub-array. P - Display the sampling of the previous sub-array. ] - Display sampling of the next IF. [ - Display sampling of the previous IF. T - Prompt for the next sub-array to be plotted. This is then entered by its numeric ID, at the keyboard. U - Select the time range to be plotted. Initially tplot plots sampling over the full range of integration times. To restrict the range press U, move the cursor to the start of the new range and press A (left mouse button), then move the cursor to the end of the required range and press A again. Sampling of the current sub-array will be re-plotted within the new range. To return to the full time range press U twice in succession. B - Break the displayed time range into scans. A scan is defined as a block of data, separated from the next block of data by more than an hour (this can be changed with the 'scangap' command). If there are no gaps this large then no change in plotting will result. Otherwise, each scan will be plotted within its own box and the gaps between scans will no longer be plotted. Scan mode will remain in effect until B is pressed again. C - Flag any un-flagged samples within a given area (see below). R - Restore any flagged samples within a given area (see below). W - Toggle the scope of edits with respect to spectral-line channels. Each plotted point comes from a single IF, and its displayed flag status is determined from the combined status of all the channels currently selected from that IF on each baseline of the telescope being sampled. By default, if you select such a point to be flagged, then all spectral-line channels of the source IF will be flagged for each of the effected baselines, irrespective of the channels which actually went into making the plot. The alternative is to edit just the channels that went into making the plot. The 'W' key toggles which of the two options is used, and a mode line above the plot describes which option is currently in effect. + - This key toggles whether the cursor is shown as a small cross or as a cross-hair that extends the full width and height of the display. Currently only the /xserve and /xwindow PGPLOT devices support this feature. EDITING ------- The Clip and Restore keys, 'C 'and 'R' enable you to edit all points inside a rectangular box selected with the cursor. With the 'C' option, all visibilities related to the selected stations over the selected integrations are flagged. Similarly, the 'R' option unflags all related visibilities in the area. To use these facilities, press the respective key and then move the cursor to one corner of the required region and press 'A' (left mouse button). Then move the cursor to the opposite corner of the required region and again press 'A'. The display will be updated to show the results. Examples of how one might use this facility include, removing a whole scan at a time for all telescopes, or flagging a bad station over the whole time range. Also see the description of the 'W' toggle, which determines whether to restrict the edits to the channels that went into making the plot, or whether to edit all channels of the displayed IF. RELATED COMMANDS ---------------- scangap - Change the time gap used to delimit neighboring scans. radplot - Display visibility amplitude/phase vs. UV radius. projplot - Display visibility amplitude/phase vs. projected UV distance. uvplot - Display the sampling of the UV plane. vplot - Display observed and model visibilities from the current IF. cpplot - Display observed and model closure phases interactively. corplot - Display the self-cal corrections of the current IF.