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Thank you for sharing this - you helped me save time in creating a similar heatmap map for radio transmitter measurements :)

Thank you so much Prof. This is really helpful.

How do you create uncertainty files

Thank you mam..its really helpful

Why doesnt this show DISP results

Dr. LISA, Thank you for such a wonderful and informative video. Are you still working with PMF? I just started using it and go through various problems and want to ask to you time by time. Is it possible to do so?

omg this video has saved me thank you so much! I couldn't make any sense of my lecture slides and this is what finally cleared things up for me after many hopeless hours of trying to interpret everything.

please make a video purely for the PCA vs PMF,and their interpretation.urgently needed.You explain very clearly.Pls help if its possible.

How can I download all daily discharge from all gauge stations in a state in bulk?

Where are you from ma'am?

Nice class 😊👍

This data is a mess 🥲

@11:41 In the homework in canvas, there isn't a 1-alpha, just for anyone who is lost. It is just alpha for acids.

Thank you mam , for the advice.. I am from Bangladesh, an undergrad student.

Hello, I am facing the following problem while using the EPA PMF 5.0. Unhandled exception has occurred in your application. If you click Continue, the application will ignore this error and attempt to continue. If you click Quit, the application will close immediately. Index was outside the bounds of the array. Can anyone help me to get rid of this?

Thank you very much Dr. Lisa. This video is wonderfull

what should be considered as uncertainty????

HI all, I frequently get asked about how to construct your uncertainty matrix. Here is my advice: calculating uncertainty is tough. We use the RSD of surrogate recoveries, but if you don't have those, you can use the Relative Percent Difference of duplicates. Often the RPD ranges from tiny to >100%, so I usually scale it so that the uncertainties range from about 10% to about 35% but the ranking of the uncertainties among the analytes is the same. I have also used information on reproducibility that we got from the published method. If all else fails, you can punt and use a sliding scale, starting with 10% for the things that you feel in your gut are certain (probably including things that are well above the LOD) and use 35% for the less certain things (including stuff near the LOD). For example, I would give a high uncertainty to things like nitrite since it is so reactive and hard to measure, and low uncertainty to things like TOC, which is pretty easy to measure. Keep in mind that PMF 5.0 takes the uncertainty in the same units as the input concentrations, so you have to multiply these percentages by the measured concentration. And you always give a much higher unc to NDs. I usually use three times the regular uncertainty for that analyte and apply it to NDs (multiplied by whatever value I'm using as a proxy for the ND, usually half the LOD). You may have to try a few unc matrixes until you find one that works. And PMF 5.0 has that field under Base Model...Concentration/Uncertainty where you can add extra modeling uncertainty. Try it with 0% extra uncertainty and then keep increasing the extra uncertainty by 5% at a time until you get something that works.

HI all, I frequently get asked about how to construct your uncertainty matrix. Here is my advice: calculating uncertainty is tough. We use the RSD of surrogate recoveries, but if you don't have those, you can use the Relative Percent Difference of duplicates. Often the RPD ranges from tiny to >100%, so I usually scale it so that the uncertainties range from about 10% to about 35% but the ranking of the uncertainties among the analytes is the same. I have also used information on reproducibility that we got from the published method. If all else fails, you can punt and use a sliding scale, starting with 10% for the things that you feel in your gut are certain (probably including things that are well above the LOD) and use 35% for the less certain things (including stuff near the LOD). For example, I would give a high uncertainty to things like nitrite since it is so reactive and hard to measure, and low uncertainty to things like TOC, which is pretty easy to measure. Keep in mind that PMF 5.0 takes the uncertainty in the same units as the input concentrations, so you have to multiply these percentages by the measured concentration. And you always give a much higher unc to NDs. I usually use three times the regular uncertainty for that analyte and apply it to NDs (multiplied by whatever value I'm using as a proxy for the ND, usually half the LOD). You may have to try a few unc matrixes until you find one that works. And PMF 5.0 has that field under Base Model...Concentration/Uncertainty where you can add extra modeling uncertainty. Try it with 0% extra uncertainty and then keep increasing the extra uncertainty by 5% at a time until you get something that works.

HI all, I frequently get asked about how to construct your uncertainty matrix. Here is my advice: calculating uncertainty is tough. We use the RSD of surrogate recoveries, but if you don't have those, you can use the Relative Percent Difference of duplicates. Often the RPD ranges from tiny to >100%, so I usually scale it so that the uncertainties range from about 10% to about 35% but the ranking of the uncertainties among the analytes is the same. I have also used information on reproducibility that we got from the published method. If all else fails, you can punt and use a sliding scale, starting with 10% for the things that you feel in your gut are certain (probably including things that are well above the LOD) and use 35% for the less certain things (including stuff near the LOD). For example, I would give a high uncertainty to things like nitrite since it is so reactive and hard to measure, and low uncertainty to things like TOC, which is pretty easy to measure. Keep in mind that PMF 5.0 takes the uncertainty in the same units as the input concentrations, so you have to multiply these percentages by the measured concentration. And you always give a much higher unc to NDs. I usually use three times the regular uncertainty for that analyte and apply it to NDs (multiplied by whatever value I'm using as a proxy for the ND, usually half the LOD). You may have to try a few unc matrixes until you find one that works. And PMF 5.0 has that field under Base Model...Concentration/Uncertainty where you can add extra modeling uncertainty. Try it with 0% extra uncertainty and then keep increasing the extra uncertainty by 5% at a time until you get something that works.

oops. 2 H2O => H3O+ + OH- Even profs make mistakes....

Pentachloroethane destroys the testicles! DESTROYS THE TESTICLES!!!

How do I get legend of these colors on Google Earth?

Can you explain more by using other examples? it is not understandable!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

Thank you very much.

My Q values always 0，could somebody help me？

Professor what is the difference between base model and bootstrap value in PMF ? Thankyou very much

Thank you so much for this concise explanation of PMF (as well as the touch on the other factor analysis methods). I wish you could cover the estimation of uncertainties of analyte measurements, if it's an essential input to PMF analysis - OK, I just saw your explanation of uncertainty estimation in the comments below...😅 THANK YOU!

I think if you right click on the PFAS fish ... you get some options, including REVERT, which allows you to redo the Wizard without importing again.

great thanks

This video just made my day..

great video, would love to see more PMF on PM 2.5

Why are you whispering

Please can I send my assignment to your mail so that you guide me through

thanks a lot Md could you give us more other videos ?

Yes! you can take my course as a self-guided tutorial. Email me at my first name dot last name at Rutgers.edu and I will send you the link.

Amazing !

Thank God for the pandemic that made you post these videos on RUclips! Thank you!

Your work is amazing! Your channel is amazing! I'm so glad I found it! It might keep me entertained the whole night :)

Is there a way to take your class under a non degree seeking student status?

Dear Doctor, Thank you very much for this video ! It's really interesting because I'm in the same case. Is it possible to have exchanges to resolve my problem ? Yours sincerely, GIOVANNANGELI Cyril

This is absolutely awesome. I'm doing (like right now) a monster MLR for a 'y' (client and everything confidential but I'll say it's a potable water contaminant of emerging concern ; ) ) at a sample point given 114 possible causation variables, so it is pretty serendipitous that I 'randomly' (I'm sure the good folks at Google know I'm in R and running MLRs, so maybe not so randomly) ran into this. I used a Pearson correlation matrix to pick likely explanatory variables and then just used R^2 and RSE for my goodness of fit. Some of the explanatory variables are correlated so I switched them back and forth to see which one gave me the best overall model and whether they are statistically significant. Then I peek at the residuals and leverage and fine tune. Learned two things today: I need to get more familiar with AIC & need to experiment with try().

Dr. Lisa, do you allow for someone outside of this class to follow along? Regardless, I appreciate all of the content of your Channel!

Mega thank you for sharing your R insights. This has really helped me create multiple histograms from a large array, all in one go. I'm using the techniques you demonstrate, here, with those from Joachim on visualisation. Link:- ruclips.net/video/y__hvGTN7ms/видео.html

This video is super helpful.....you saved me hours of spreadsheet manipulation. Thank you.

can you in video explain how to calculate specie specific uncertainty in PMF in detail. Thank you in advance.

By chance offer free lance work? I have some data I would like a regression analysis completed on, and then help create a prediction algorithm based on the freundlich equation.

Thank you!

Thanks a lot. I have one question about PMF. What does E (leftover or residual) values in the case of PFAS in lake fish mean? Does the E values mean we have some factors remained unidentified? Look forward to your reply. Thanks.

It is really helpful. Thank you Prof. Lisa