Home |
Search |
Today's Posts |
|
#1
![]()
Posted to microsoft.public.excel.misc
|
|||
|
|||
![]()
I have a population that I belive it will be represent a Gaussian (normal)
distribution if I am able to identify and remove the outliers properly. I now understand I cannot use the Grubb's Test as outlined in a couple of websites I found (see http://www.graphpad.com/articles/outlier.htm and http://www.itl.nist.gov/div898/softw...r/grubtest.htm) because I have many outliers and the distribution is not normal. Based on a discussion I found on this forums (subject: "how do I identify statistical outliers with excel", dated: 1/7/2007), I decided to use the the Interquartile Range method (IQR); but the following formula is giving me an annoying #VALUE! error: =if(or(D1 < A1 - 3*B1, D1 A2 + 3*B1), "outlier?", "") I modified that formula so that D1 is the value I am testing, A1 is the value of the 1st quartile, B1 is the value between the 3rd quartile minus the 1st quartile, and A2 is the value of the 3rd quartile. But I got the same error message. Then I removed the spaces in the formula, but I still get the same error. It is very frustating, and I don't know how to fix this. Any suggestions? |
#2
![]()
Posted to microsoft.public.excel.misc
|
|||
|
|||
![]()
This works for me: =IF(OR(D1<(A1-(3*B1)),D1(A2+(3*B1))),"outlier?","")
You're missing many parentheses in your formula below; also the spaces make it hard to read what you're trying to do. See if my proposal works. Dave -- A hint to posters: Specific, detailed questions are more likely to be answered than questions that provide no detail about your problem. "Quco" wrote: I have a population that I belive it will be represent a Gaussian (normal) distribution if I am able to identify and remove the outliers properly. I now understand I cannot use the Grubb's Test as outlined in a couple of websites I found (see http://www.graphpad.com/articles/outlier.htm and http://www.itl.nist.gov/div898/softw...r/grubtest.htm) because I have many outliers and the distribution is not normal. Based on a discussion I found on this forums (subject: "how do I identify statistical outliers with excel", dated: 1/7/2007), I decided to use the the Interquartile Range method (IQR); but the following formula is giving me an annoying #VALUE! error: =if(or(D1 < A1 - 3*B1, D1 A2 + 3*B1), "outlier?", "") I modified that formula so that D1 is the value I am testing, A1 is the value of the 1st quartile, B1 is the value between the 3rd quartile minus the 1st quartile, and A2 is the value of the 3rd quartile. But I got the same error message. Then I removed the spaces in the formula, but I still get the same error. It is very frustating, and I don't know how to fix this. Any suggestions? |
#3
![]()
Posted to microsoft.public.excel.misc
|
|||
|
|||
![]()
Thanks Dave,
This is is very interesting, now I am not getting the error message #VALUE!; now I am getting the word FALSE in the cell as a result instead getting the text "outlier?". "Dave F" wrote: This works for me: =IF(OR(D1<(A1-(3*B1)),D1(A2+(3*B1))),"outlier?","") You're missing many parentheses in your formula below; also the spaces make it hard to read what you're trying to do. See if my proposal works. Dave -- A hint to posters: Specific, detailed questions are more likely to be answered than questions that provide no detail about your problem. "Quco" wrote: I have a population that I belive it will be represent a Gaussian (normal) distribution if I am able to identify and remove the outliers properly. I now understand I cannot use the Grubb's Test as outlined in a couple of websites I found (see http://www.graphpad.com/articles/outlier.htm and http://www.itl.nist.gov/div898/softw...r/grubtest.htm) because I have many outliers and the distribution is not normal. Based on a discussion I found on this forums (subject: "how do I identify statistical outliers with excel", dated: 1/7/2007), I decided to use the the Interquartile Range method (IQR); but the following formula is giving me an annoying #VALUE! error: =if(or(D1 < A1 - 3*B1, D1 A2 + 3*B1), "outlier?", "") I modified that formula so that D1 is the value I am testing, A1 is the value of the 1st quartile, B1 is the value between the 3rd quartile minus the 1st quartile, and A2 is the value of the 3rd quartile. But I got the same error message. Then I removed the spaces in the formula, but I still get the same error. It is very frustating, and I don't know how to fix this. Any suggestions? |
#4
![]()
Posted to microsoft.public.excel.misc
|
|||
|
|||
![]()
Well, FALSE is an improvement because it indicates the formula is calculating.
IF statements work with the following logic: IF A, Then B, Else C. Stated another way: If A, value if A is true, value if A is false. Absent a value in the false argument, FALSE is returned. So: check your formula and the values in the cells that the formula refers to. Are the values in the cells numbers? Are they formatted as numbers? Do you have all your parentheses in order? Etc. Dave -- A hint to posters: Specific, detailed questions are more likely to be answered than questions that provide no detail about your problem. "Quco" wrote: Thanks Dave, This is is very interesting, now I am not getting the error message #VALUE!; now I am getting the word FALSE in the cell as a result instead getting the text "outlier?". "Dave F" wrote: This works for me: =IF(OR(D1<(A1-(3*B1)),D1(A2+(3*B1))),"outlier?","") You're missing many parentheses in your formula below; also the spaces make it hard to read what you're trying to do. See if my proposal works. Dave -- A hint to posters: Specific, detailed questions are more likely to be answered than questions that provide no detail about your problem. "Quco" wrote: I have a population that I belive it will be represent a Gaussian (normal) distribution if I am able to identify and remove the outliers properly. I now understand I cannot use the Grubb's Test as outlined in a couple of websites I found (see http://www.graphpad.com/articles/outlier.htm and http://www.itl.nist.gov/div898/softw...r/grubtest.htm) because I have many outliers and the distribution is not normal. Based on a discussion I found on this forums (subject: "how do I identify statistical outliers with excel", dated: 1/7/2007), I decided to use the the Interquartile Range method (IQR); but the following formula is giving me an annoying #VALUE! error: =if(or(D1 < A1 - 3*B1, D1 A2 + 3*B1), "outlier?", "") I modified that formula so that D1 is the value I am testing, A1 is the value of the 1st quartile, B1 is the value between the 3rd quartile minus the 1st quartile, and A2 is the value of the 3rd quartile. But I got the same error message. Then I removed the spaces in the formula, but I still get the same error. It is very frustating, and I don't know how to fix this. Any suggestions? |
#5
![]()
Posted to microsoft.public.excel.misc
|
|||
|
|||
![]()
It appears to be right. I don't know what is wrong. I am comparing:
=IF(OR(G3027<(G3035-(3*G3040)),G3027(G3037+(3*G3040))),"outlier?","") =IF(OR(D1<(A1-(3*B1)),D1(A2+(3*B1))),"outlier?","") My formula vs. your notation for the formula I am using. The cells are all values resulting from other formulas on my spreadsheet; all are numbers. I was reading more about the OR function, it appears that the OR function always return a True or FALSE value. But how do I make understand Excel that it needs to treat the content of the OR formula as valid (in this case) so that the result is printed as "outlier?" ??? Maybe there is something I am missing... do you think is because my cells are not number-values but numbers resulting from other formulas? everything else seems to be working properly on my Excel spreadsheet. "Dave F" wrote: Well, FALSE is an improvement because it indicates the formula is calculating. IF statements work with the following logic: IF A, Then B, Else C. Stated another way: If A, value if A is true, value if A is false. Absent a value in the false argument, FALSE is returned. So: check your formula and the values in the cells that the formula refers to. Are the values in the cells numbers? Are they formatted as numbers? Do you have all your parentheses in order? Etc. Dave -- A hint to posters: Specific, detailed questions are more likely to be answered than questions that provide no detail about your problem. "Quco" wrote: Thanks Dave, This is is very interesting, now I am not getting the error message #VALUE!; now I am getting the word FALSE in the cell as a result instead getting the text "outlier?". "Dave F" wrote: This works for me: =IF(OR(D1<(A1-(3*B1)),D1(A2+(3*B1))),"outlier?","") You're missing many parentheses in your formula below; also the spaces make it hard to read what you're trying to do. See if my proposal works. Dave -- A hint to posters: Specific, detailed questions are more likely to be answered than questions that provide no detail about your problem. "Quco" wrote: I have a population that I belive it will be represent a Gaussian (normal) distribution if I am able to identify and remove the outliers properly. I now understand I cannot use the Grubb's Test as outlined in a couple of websites I found (see http://www.graphpad.com/articles/outlier.htm and http://www.itl.nist.gov/div898/softw...r/grubtest.htm) because I have many outliers and the distribution is not normal. Based on a discussion I found on this forums (subject: "how do I identify statistical outliers with excel", dated: 1/7/2007), I decided to use the the Interquartile Range method (IQR); but the following formula is giving me an annoying #VALUE! error: =if(or(D1 < A1 - 3*B1, D1 A2 + 3*B1), "outlier?", "") I modified that formula so that D1 is the value I am testing, A1 is the value of the 1st quartile, B1 is the value between the 3rd quartile minus the 1st quartile, and A2 is the value of the 3rd quartile. But I got the same error message. Then I removed the spaces in the formula, but I still get the same error. It is very frustating, and I don't know how to fix this. Any suggestions? |
#6
![]()
Posted to microsoft.public.excel.misc
|
|||
|
|||
![]()
It's hard to say what the issue is. What are the actual values in G3027,
etc. Are they formatted as numbers, as opposed to text? OR tests for TRUE or FALSE values: =OR(1+2=10,2+2=4) resolves to TRUE because one calculation is TRUE. On the other hand =OR(1+2=2,2+2=24332) resolves to FALSE because neither calculation is true. Therefore your formula says: "If [calculation A] OR [calculation B] is correct, or both are correct, then consider it an outlier, else return an empty string." Dave -- A hint to posters: Specific, detailed questions are more likely to be answered than questions that provide no detail about your problem. "Quco" wrote: It appears to be right. I don't know what is wrong. I am comparing: =IF(OR(G3027<(G3035-(3*G3040)),G3027(G3037+(3*G3040))),"outlier?","") =IF(OR(D1<(A1-(3*B1)),D1(A2+(3*B1))),"outlier?","") My formula vs. your notation for the formula I am using. The cells are all values resulting from other formulas on my spreadsheet; all are numbers. I was reading more about the OR function, it appears that the OR function always return a True or FALSE value. But how do I make understand Excel that it needs to treat the content of the OR formula as valid (in this case) so that the result is printed as "outlier?" ??? Maybe there is something I am missing... do you think is because my cells are not number-values but numbers resulting from other formulas? everything else seems to be working properly on my Excel spreadsheet. "Dave F" wrote: Well, FALSE is an improvement because it indicates the formula is calculating. IF statements work with the following logic: IF A, Then B, Else C. Stated another way: If A, value if A is true, value if A is false. Absent a value in the false argument, FALSE is returned. So: check your formula and the values in the cells that the formula refers to. Are the values in the cells numbers? Are they formatted as numbers? Do you have all your parentheses in order? Etc. Dave -- A hint to posters: Specific, detailed questions are more likely to be answered than questions that provide no detail about your problem. "Quco" wrote: Thanks Dave, This is is very interesting, now I am not getting the error message #VALUE!; now I am getting the word FALSE in the cell as a result instead getting the text "outlier?". "Dave F" wrote: This works for me: =IF(OR(D1<(A1-(3*B1)),D1(A2+(3*B1))),"outlier?","") You're missing many parentheses in your formula below; also the spaces make it hard to read what you're trying to do. See if my proposal works. Dave -- A hint to posters: Specific, detailed questions are more likely to be answered than questions that provide no detail about your problem. "Quco" wrote: I have a population that I belive it will be represent a Gaussian (normal) distribution if I am able to identify and remove the outliers properly. I now understand I cannot use the Grubb's Test as outlined in a couple of websites I found (see http://www.graphpad.com/articles/outlier.htm and http://www.itl.nist.gov/div898/softw...r/grubtest.htm) because I have many outliers and the distribution is not normal. Based on a discussion I found on this forums (subject: "how do I identify statistical outliers with excel", dated: 1/7/2007), I decided to use the the Interquartile Range method (IQR); but the following formula is giving me an annoying #VALUE! error: =if(or(D1 < A1 - 3*B1, D1 A2 + 3*B1), "outlier?", "") I modified that formula so that D1 is the value I am testing, A1 is the value of the 1st quartile, B1 is the value between the 3rd quartile minus the 1st quartile, and A2 is the value of the 3rd quartile. But I got the same error message. Then I removed the spaces in the formula, but I still get the same error. It is very frustating, and I don't know how to fix this. Any suggestions? |
#7
![]()
Posted to microsoft.public.excel.misc
|
|||
|
|||
![]()
You shouldn't be getting FALSE from that formula, whatever the inputs,
because both outcomes of the IF are defined as strings. Did you literally copy and paste from the formula bar to the newsgroup posting, or might something have been mistyped? Try copying back from your posting below to the spreadsheet, or try copying =IF(OR(G3027<G3035-3*G3040,G3027G3037+3*G3040),"outlier?","") into your spreadsheet to check. -- David Biddulph "Quco" wrote in message ... It appears to be right. I don't know what is wrong. I am comparing: =IF(OR(G3027<(G3035-(3*G3040)),G3027(G3037+(3*G3040))),"outlier?","") =IF(OR(D1<(A1-(3*B1)),D1(A2+(3*B1))),"outlier?","") My formula vs. your notation for the formula I am using. The cells are all values resulting from other formulas on my spreadsheet; all are numbers. I was reading more about the OR function, it appears that the OR function always return a True or FALSE value. But how do I make understand Excel that it needs to treat the content of the OR formula as valid (in this case) so that the result is printed as "outlier?" ??? Maybe there is something I am missing... do you think is because my cells are not number-values but numbers resulting from other formulas? everything else seems to be working properly on my Excel spreadsheet. "Dave F" wrote: Well, FALSE is an improvement because it indicates the formula is calculating. IF statements work with the following logic: IF A, Then B, Else C. Stated another way: If A, value if A is true, value if A is false. Absent a value in the false argument, FALSE is returned. So: check your formula and the values in the cells that the formula refers to. Are the values in the cells numbers? Are they formatted as numbers? Do you have all your parentheses in order? Etc. Dave -- A hint to posters: Specific, detailed questions are more likely to be answered than questions that provide no detail about your problem. "Quco" wrote: Thanks Dave, This is is very interesting, now I am not getting the error message #VALUE!; now I am getting the word FALSE in the cell as a result instead getting the text "outlier?". "Dave F" wrote: This works for me: =IF(OR(D1<(A1-(3*B1)),D1(A2+(3*B1))),"outlier?","") You're missing many parentheses in your formula below; also the spaces make it hard to read what you're trying to do. See if my proposal works. Dave -- A hint to posters: Specific, detailed questions are more likely to be answered than questions that provide no detail about your problem. "Quco" wrote: I have a population that I belive it will be represent a Gaussian (normal) distribution if I am able to identify and remove the outliers properly. I now understand I cannot use the Grubb's Test as outlined in a couple of websites I found (see http://www.graphpad.com/articles/outlier.htm and http://www.itl.nist.gov/div898/softw...r/grubtest.htm) because I have many outliers and the distribution is not normal. Based on a discussion I found on this forums (subject: "how do I identify statistical outliers with excel", dated: 1/7/2007), I decided to use the the Interquartile Range method (IQR); but the following formula is giving me an annoying #VALUE! error: =if(or(D1 < A1 - 3*B1, D1 A2 + 3*B1), "outlier?", "") I modified that formula so that D1 is the value I am testing, A1 is the value of the 1st quartile, B1 is the value between the 3rd quartile minus the 1st quartile, and A2 is the value of the 3rd quartile. But I got the same error message. Then I removed the spaces in the formula, but I still get the same error. It is very frustating, and I don't know how to fix this. Any suggestions? |
Reply |
Thread Tools | Search this Thread |
Display Modes | |
|
|
![]() |
||||
Thread | Forum | |||
how do I identify statistical outliers with excel? | Excel Discussion (Misc queries) | |||
how do I identify statistical outliers with excel | Excel Discussion (Misc queries) | |||
Boxplots with outliers | Charts and Charting in Excel | |||
outliers/histograms | Excel Discussion (Misc queries) | |||
How do I calculate outliers in Excel? | Excel Discussion (Misc queries) |