station, umax, vmax, docursor Plot observed UV points on the UV plane. EXAMPLE ------- 0> uvplot "BONN" 0> This example plots the positions of visibilities in the UV plane, plotting all but the data associated with BONN in green. BONN data from the first sub-array is plotted in a different color to highlight it. If the display device has a cursor then interactive mode will be invoked after the initial display has been completed. PARAMETERS ---------- station - (Optional) The name of a station to highlight in the plot. If not given or given as an empty string "", no station will initially be highlighted. (Stations can be specified subsequently with the cursor). umax - (Optional) Default=0 (0 -specifies the whole range). The maximum U coordinate to display. The plot will go from -umin to +umin. Unless changed with the mapunits command, the units are million-wavelengths. vmax - (Optional) Default=0 (0 -specifies the whole range). The maximum V coordinate to display. The plot will go from -vmin to +vmin. Unless changed with the mapunits command, the units are million-wavelengths. docursor - (Optional) Default=TRUE. If the display device has a cursor but you don't want to enter the interactive cursor mode, make this FALSE. CONTEXT ------- This task displays the UV coverage of all un-flagged visibilities selected with the 'select' command. For each baseline, one point is plotted per IF. Where multiple spectral-line channels are selected from a given IF, the visibility is the average of those channels and is displayed at the corresponding mean U and V coordinates. INTERACTIVE MODE ---------------- If your display device has a cursor, then there are a number of interactive options that you can use. These are selected by moving the cursor into the plot window, and pressing the following keys: X - Quit the uvplot session, and return to the difmap prompt. L - Re-display the plot. Z - Zoom in on a rectangular sub-plot of the displayed region. After pressing 'Z' either press 'Z' again to revert to the original un-zoomed display, or select the two vertexes of the desired sub-plot area by sequentially pressing the 'A' key (left-mouse-button) over each. To cancel an incomplete selection, press 'D' (middle-mouse-button). . - Toggle the marker symbol used to display the data between the smallest available and the next largest. By default the smallest possible marker symbol is used for speed, but if if the data are sparse then the larger marker symbol may be more convenient. H - (Help) Briefly list all keyboard options. n - Highlight visibilities from the next telescope in the currently highlighted sub-array. Initially no telescope is highlighted. If this key then pressed, the visibilities of the first telescope of the first sub-array will be highlighted. Pressing this key again highlights the second telescope, etc.. When the last telescope of the current sub-array has been plotted, the first telescope of the next sub-array will be plotted. So by repeatedly pressing this key you will eventually have seen each telescope of all sub-arrays individually highlighted. p - This has the reverse the effect to the 'n' key, highlighting the visibilities of the previous telescope in the current sub-array, and wrapping back to the last telescope in the previous sub-array, after the first telescope of the current sub-array is highlighted. N - [Upper-case n] Similar to the lower-case 'n' key this key results in the first telescope of the next sub-array in the observation to be highlighted. In this way you can jump between sub-arrays without having to see all the telescopes of the intermediate sub-arrays highlighted one at a time. P - [Upper-case p] This has the reverse effect of the 'N' key, allowing one to directly step backwards through sub-arrays. T - To have a specific telescope of a specific sub-array highlighted without having to step through all the intermediate telescopes and sub-arrays, press this key. On the text window you will then be prompted for the name of the telescope to be highlighted. Telescopes are specified by an optional sub-array number delimited by a colon, followed by an unambiguous telescope name prefix. If the sub-array number and colon are omitted then the sub-array from which telescopes are currently being highlighted will be assumed. For instance, both 3:BONN and BON refer to a telescope named BONN in sub-array 3 if another telescope of sub-array 3 is currently being highlighted. Also, provided that sub-array 2 does not contain more than one telescope starting with the prefix JBN, 2:JBN is sufficient to refer to a telescope called JBNK1 in sub-array 2. S - This causes uvplot to display details about the visibility nearest to the cursor. It shows the sub-array, baseline, IF number and date of the visibility. C - This initiates cut area selection, through which a rectangular area may be selected within which to flag data. After pressing 'C' you will be expected to enter the locations of two opposite corners of the area, by pressing 'A' (left-mouse-button) over the corresponding points of the plot. To cancel a half selected area press 'D' (central-mouse-button). Once two corners have been selected, all visibilities displayed in that area will be flagged and will then disappear from the plot. W - Toggle the scope of edits with respect to spectral-line channels. Each point in the plot comes from a single IF, and its position in the plot is determined by the mean frequency of the channels currently selected from that IF. By default, if you select such a point to be flagged, then all spectral-line channels of the source IF will be flagged, 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. + - Toggle whether the cursor is shown as a small cross or a cross-hair that extends the full width and height of the display. Currently only the /xserv and /xwin PGPLOT devices support this feature. OTHER DISPLAY COMMANDS ---------------------- radplot - Display visibility amplitude vs. radius. projplot - Display visibility amplitude/phase vs. projected UV distance. vplot - Display observed and model visibilities from the current IF. tplot - Display the time-sampling of each telescope of the current IF. corplot - Display the self-cal corrections of the current IF. cpplot - Display observed and model closure phases interactively.