October/November 2004 ALMA Offline software test NAME: James Di Francesco, National Research Council of Canada Questionnaire on testing experience 1. Please list briefly your background in the following areas: A. Radio Interferometry ((sub)millimeter or centimeter) - ~10 years experience with millimeter interferometry - ~8 years experience with high-frequency centimeter interferometry B. Experience with VLA and/or PdBI data - have reduced and analyzed 3-4 VLA projects - have reduced and analyzed 3 PdBI projects C. Astronomical Data Reduction packages: - AIPS - yes - MIRIAD - yes - MMA - yes - Gildas/Clic - yes - AIPS++ - none D. How much experience have you had with the AIPS++ software package before this test? - none 2. Please identify which dataset you processed during this test: B. BIMA CO(1-0) observations of NGC 4826 3. Were you able to complete the fill, editing, and calibration of the data? If not, why? Please comment on specific steps if desired (comments can be positive or negative): A. Filling the data into AIPS++ format - data filling was not difficult, no problems encountered - it would be useful to have a time-organized summary printed out into an external file for reference when considering large swaths of data to autoflag (i.e., akin to the "listobs" task of MIRIAD). At present, a summary is written to the messages log and it can be difficult to scroll back up to the time sequence if the data contain a lot of pointings or the track is long B. Editing and visualizing your data - interactive flagging was terrific; excellent job! It would be very helpful if it were possible to change or increase the size of the plotted dots, however, since they were so small it was sometimes difficult to see individual points. Furthermore, it would be very useful if it were possible, e.g., when looking at a succession of baselines, to be able to set the duration of the display between iterations. Also, it would be extremely helpful if it were possible to flag or unflag data over a succession of baselines rather than have to display and edit one baseline at a time. - at present it is not possible to sum up different spectral windows for display in the interactive flagging tool For example, the spectral selection window allows you to list the number of channels, the starting channel, and the num- ber of channels to skip, but it does not let you indicate the number of channels to average together. - I can see a danger in interactive flagging since it is now so easy to deal with data, it is easy to overflag the data! - autoflagging data was fairly straightforward, although the "af.run()" step can take an enormous amount of time C. Atmospheric phase corrections (PdBI data only) - not applicable for BIMA data D. Gain (phase and amplitude) calibration - gain calibration was not difficult. In my case it was a little difficult to judge how well it was working since I only looked at the amp and phase gain solutions for the calibrators. Had I more time, I would have instituted a step where I would have examined the corrected amplitudes and phases of the target data themselves. The mechanism for gain solving is not well described and the process is is somewhat "black box" (a problem with MIRIAD. I like how MMA displays the polynomial fits to the gains and lets you interactively decide which order provides the best fits.) E. Absolute flux calibration - absolute flux calibration not difficult. In my case the flux of 3C273 was found by "private communication" and not from the data itself (e.g., from an observed planet), so I could not test aips++ tasks for determining flux. F. Bandpass calibration - also not applicable for BIMA data 4. Were you able to subtract continuum in the uv-plane (if applicable)? If not, why? - not applicable 5. Were you able to split out the calibrated data (if desired)? If not, why? - yes, accomplished without problems 6. Were you able to image the data? If not, why? Please identify any problems you had during imaging. - yes, no problems with imaging once I figured out the tools 7. Were you able to analyze the images adequately to determine if the results you obtained were scientifically reasonable (e.g. display the image, calculate RMS and peak, make a moment map or take a spectrum)? If not, why? - yes, I was able to use the moment tasks, make moment images, and display them. Very nice data viewer, by the way. 8. Please summarize the final results of your image(s): - NB: these are computed over the entire cube/plane not subregions Full Cube 0mom 1mom - unit (Jy/b) (Jy/b)*(km/s) (km/s) - RMS: 0.088 16.3 421 - Peak Value: 2.07 186.1 583 - Peak Value location: (113 115 1 25) (139,121,1) (64,29,1) 9. Did you have adequate support during your test? If you contacted the AIPS++ groups for questions or to fix a bug, please comment on the interaction and whether it was helpful. - I only contacted the aips++ group twice and my queries were answered quickly and well. 10.Was AIPS++ easy to install? If not, why? - yes, our systems administrator did this for me. The DVD that was sent to me, however, had a DVD+RW format which my own drive could not read. 11.The Synthesis Reduction Cookbook you used for this test is the first version of a comprehensive cookbook for ALMA users. Please evaluate the organization, content, and presentation of the cookbook. It is meant to be the first documentation users will see when they want to reduce ALMA data, it provides background on the code capabilities, and extensive examples. The on-line documentation provides more details and code descriptions. With this in mind, please answer the questions below. If you have detailed comments, please attach them to the end of this questionnaire. - Was the documentation adequate for you to complete your test? yes, the documentation was extremely thorough and helpful - Was the cookbook good? yes, the cookbook does a good job of providing both the background and the steps necessary to make progress with data - Do you have any suggestions for how to improve the cookbook? 1. provide at the beginning of each chapter a list of tasks it details 2. an index can be very helpful (it is understandable it does not yet exist given the early nature of the book) 3. The section of annotated scripts will be very useful and I suggest expanding it as much as possible (either in print or online) to cover many different astronomical situations 4. The chapter on aips++ tools should include lists of available options for each task and tool with some description. At times I found it difficult to gauge what options were at my disposal. - Was the on-line documentation good: * User Reference Manual? I did not use it * Supporting documentation? The data description compiled by D. Shepherd was very useful to me as I went through my datasets, both beforehand and afterwards. 12.Roughly how much time did you take to perform the following steps: - Installing aips++: 1 hour - Fill, editing, & calibration: 15 hours - Continuum imaging: n/a - Spectral line imaging: 1 hour - Analysis: 1 hour - Filling out this questionnaire: 2 hours - Evaluating and grading the scientific requirements: - Total time: 20 hours 13.Please rate your overall testing experience: - good 14.Was the test well designed and executed by those in the ALMA offline subsystem (e.g. the subsystem scientist and the Offline subsystem group). If not, can you provide any suggestions for improving the next test? - the test was well designed. Although it would have made the test longer for me, I suggest in the future including BIMA datasets that require both passband calibration and absolute flux calibration so the relevant aips++ procedures could have been tested. 15.Do you have any additional comments that may help improve test of the offline software in the future? - I found the 'imagr.weight' task did not execute when I entered in values as listed in the cookbook. Instead I received the following messages. In the end, I did not succeed in getting this to work so I skipped it. Fortunately, it did not seem that important as I was able to image the mosaic correctly. ********************************************************************************************* - imgr.weight(mode='natural',mosaic=T); : named arg "mode" does not match any formal in call to function (val type = uniform, v al rmode = none, val noise = 0.0Jy, val robust = 0, val fieldofview = 0rad, val npixels = 0, val mosaic = F, val async = !dowait) { { { { { { { { if ((type == briggs) && ((rmode == none) || (rmode == ))) (rmode := norm); (self.weightRec.type := type);} (self.weightRec.rmode := rmode);} (self.weightRec.noise := noise);} (self.weightRec.robust := robust);} (self.weightRec.fieldofview := fieldofview);} (self.weightRec.npixels := npixels);} if mosaic {{ { { { (saved.setdataRec := self.setdataRec); for ( field in self.setdataRec.fieldid ) {{ { public.setdata(fieldid = field, spwid = self.setdataRec.spwid); public.weight(type = self.weightRec.type, rmode = self.weightRec.rmode, noise = self.weightRe c.noise, robust = self.weightRec.robust, fieldofview = self.weightRec.fieldofview, npixels = self.weightRec.npixels, mosaic = F);} }}} public.setdata(mode = saved.setdataRec.mode, nchan = saved.setdataRec.nchan, start = saved.se tdataRec.start, step = saved.setdataRec.step, mstart = saved.setdataRec.mstart, mstep = saved .setdataRec.mstep, spwid = saved.setdataRec.spwid, fieldid = saved.setdataRec.fieldid, mssele ct = saved.setdataRec.msselect);} return T} }}} return defaultservers.run(self.agent, self.weightRec, async)} File: imager.g, Line 283 Stack: .() ********************************************************************************************* - I had to add "infile=" to "im:=image(infile='ngc4826.cm');" to get the following steps to work out correctly. - In general, aips++ does not provide much guidance when incorrect values are entered. For example, I was hung up for hours because I entered "3c273" when I should have entered "3C273" as the name of the flux calibrator in the flux calibration step. I couldn't discern where the fault was from the aips++ feedback. - I was unable to recover well from stopping long process runs via ctrl-C. This happened when I tried to test imaging ~240 channels and I decided to stop it since it was taking a long time. After hitting ctrl-C, aips++ became confused, and subprocesses did not seem to continue despite the interruption on the command line. In the end, these processes had to be killed individually and aips++ restarted afresh. - although it is OK to "cut and paste" a script, it would be REALLY nice to run aips++ as a shell script, allowing you to repeat steps without having to re-enter line after line. - Note that I added data from both tracks although those from 98apr22 were clearly inferior to those from 98apr16. In fact, my imaging of the phase calibrator 1230+123 revealed a secondary peak to the west, which may be due to phase errors on some antenna I did not have time to track down.