And at this point I still do not know what I am doing wrong. PRINT line in the XYCE script, the file DCIV-S_dc.txt, into the file. So, I believe my problems, poor plotted or no plotted data, stems from an error converting the data from the. When I correct the data in this file, shown in the attached, and plot it, I get a correct Qucs plot. But the file has somehow been corrupted by changing the "sweep" variable to 20 increments and the "Number" variable to 12 increments. The file shows the data that is being plotted for the simulation with DC V1 swept from 0 to 4 V in 0.1 V increments, independent "sweep" variable of 41 increments, and I1 stepped from 0.0 to 0.15e-3 A in 0.03e-3 A increments, independent "Number" variable of 6 increments. I have also discovered the retrace problem when there is data that is plotted using the Qucs Cartesian diagram. dat.xyce file information is included in the two renamed attachments, that shows a file with simulation data, and, that shows a file without simulation data. dat.xyce files contain simulation data.Įxamples of the. And, that when the DCIV-S_dc.txt and DCIV-S-Xyce_dc.txt files are missing in the spice4qucs directory the two previous. dat.xyce files are devoid of simulation data. Since its initial public release in 2003 around twenty. Qucs is the brain-child of German Engineers Michael Margraf and Stefan Jahn. That when the DCIV-S_dc.txt and DCIV-S-Xyce_dc.txt are present in the spice4qucs directory the previous two. The ‘Quite universal circuit simulator’ Qucs (pronounced: kju:ks) is an open source circuit simulator developed by a group of engineers, scientists and mathematicians under the GNU General Public License (GPL). I now understand that the Qucs Cartesian diagrams utilize the data files underneath the prj directory: ie. But when the simulation does produce output data then the DCIV-S_dc.txt file dissappears. On top of this, I have noticed that when the simulation does not yield output data, the file DCIV-S_dc.txt exists in the spice4qucs folder. If I copy the four deactivated components over to my previous schematic I can get the same output as the new schematic but there is a completely different relationship to which deleting deactivated components allow or disallow output data. But if I delete the SW1 or SW2 Parameter Sweep components, I do not get any output as shown in Attachement 5. If I delete the dc simulation component or the SW# Parameter Sweep component I get the same output results. But there is a retrace problem within the data: not a problem with output from other simulation engines. This simulation results in some output, shown in Attachment 4, although the first plot should be an inverted set of DCIV curves for a BJT transistor. Attached is another schematic picture, Attachment 3, of essentially the same circuit but with a deactivated Qucs dc simulation component and three deactivated Qucs Parameter Sweep components. ![]() I should add that the parameters are a mix of nominal, binary, ordinal and rational variables.And the problem is getting even wierder. Unfortunately, standard PCA reacts "poorly" to missing data. To make matters worse, student performance at various exams (e.g., NBME Step1 and Step2) is only weakly correlated (r^2 ~ 0.3), so "filling" the table with calculated values would be questionable. However, about 1/3 of the students fail the course at various time-points, so that there are a lot of missing data. ![]() Normally, I'd perform a PCA in the hope of uncovering hidden variables that determine clustering. Clustering correlates poorly with study success and with any of the other parameters. ![]() I have performed a cluster analysis (using Gower's universal similarity index and average linking) showing that students fall into 3 main groups (at ~ 0.2), each with several subgroups (at ~ 0.8). For a prospective study of parameters affecting student's success in graduate school I am looking at a population of about 1500 med students.
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