Form calculation widget: Log() function is named incorrectly

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    mbewley
    Asked on October 12, 2017 at 12:27 PM

    I've written this Navy Circumference Formula exactly as its written in Excel and can't get it to work/calculate properly in JotForm. I need assistance with correcting this formula -- what am I missing/doing wrong?

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    Kiran
    Answered on October 12, 2017 at 02:02 PM

    I see that the form is showing some calculated result as I enter some values to it. However, I am not sure if it is calculating correctly. If you can provide us with the formula that you are working on, we can take a look and examine the form calculation.

    We will wait for your response. Thank you! 

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    EltonCris
    Answered on October 12, 2017 at 03:38 PM

    That's one pretty complex calculation. :)

    Anyway, my suggestion is to break down the formula. This is to ensure that you are getting the right number on every calculation.

    Example:

    1. First calculation field gets the %Fat value

    2. Second calculation gets the log(abdomen-neck)

    3. Third gets the log(height)

    And then on your final calculation, you simply use the value on each of these fields and then calculation them. This at least simplifies the calculation process and probably gives a finer result. 

    Please try it and let us know if we can be of further help.

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    mbewley
    Answered on October 25, 2017 at 10:43 PM
    Thanks for everyone’s assistance. I tried your suggestion Elton Cris but your suggestion didn't seem to work. In fact, the problem appears to be with the log equation — it simply doesn’t work.
    Suggestions welcomed.
    Regards,
    Bewley
    ...
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    Kiran
    Answered on October 26, 2017 at 12:36 AM

    Could you share the form URL that you have already worked with Elton's suggestion so that we may be able to fix it? Also, if you can provide us the Excel sheet with the formula we can check that might help us. You may email the Excel sheet to support@jotform.com with the subject title "Support forum - 1271671".

    Thanks!

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    mbewley
    Answered on October 26, 2017 at 07:22 AM

    Thanks for your help Kiran. I already scraped the "Elton's" form since it didn't work. I've included all the excel formulas in this thread but will upload the excel sheet per your instructions.

    A simple test for the JotForm log function is create a field and enter a value. Next, create a calculating field with log function and no calculations happen in JotForm. I do the same in Excel and it works, which led me to state in my previous post the log JotForm function doesn't work.

    Your assistance is greatly appreciated.

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    Kiran
    Answered on October 26, 2017 at 09:18 AM

    Thank you for sharing the spreadsheet with us. Please allow me some time to work on the form and see if I can get you something. I'll update you here once I have any news in this regard.

    Thank you!

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    mbewley
    Answered on October 26, 2017 at 03:29 PM

    Thank you very much, Kiran for your time and willingness to assist. Greatly appreciated!!!

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    Kiran
    Answered on October 30, 2017 at 02:47 PM

    Thank you for your patience. As I tried to create the form to use the same formula, I notice that the log() value is being calculated incorrectly which is why the calculation is failing on the form.

    Here is the form that I was trying to create: https://form.jotform.com/72983631607968

    I am forwarding the issue to our backend team to take a look at it. Once we have any update from them, I'll update the form and let you know here. 

    Thank you!

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    mbewley
    Answered on October 30, 2017 at 02:49 PM

    I knew I wasn't crazy when I said the log() function didn't seem to work ;-)

    Thank you, Kiran for your all your time and assistance -- much appreciated!!!

    Regards,

    Mike

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    mbewley
    Answered on May 08, 2018 at 02:30 PM

    Kiran, has anyone figured out the problem to the log() function?


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    Victoria_K
    Answered on May 08, 2018 at 03:46 PM

    Hello,

    I was checking the log() function of Form Calculation widget and it seems that function calculates properly. Although, it's naming on the list is confusing (I would name it "ln" as it is using base of "e"), the description is much more informative:

    1525808418screenshotzx3w1.png

    This way, I can suggest to calculate a logarithm base 10 with the following formula:

    1525808528screenshotb7fsx.png

    LN10 is also available on the list of functions.

    It can be also of help to look through math functions descriptions at our guide: Form-Calculation-Math-Function-Reference

    Here is my test form: https://form.jotform.com/81276327384967

    Please check if it solves your question and let us know if you need further assistance.

    Thank you.

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    Victoria_K
    Answered on May 09, 2018 at 09:07 AM

    Hello Mike,

    I have checked the function and it's behaviour first. Then I tested to see if I get same results in excel and Form Calculation widget using parts of your formula. The log() produces same results with the formula I provided, so it should work for larger calculations as well:

    1525870714screenshotjttub.png

    As I was not sure if you still need to perform the same calculation, I have not re-created the steps of this thread. But, if you provide us a link to the form you're currently working on, we can assist.

    Get back to us if needed.

    Thank you!

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    Victoria_K
    Answered on May 09, 2018 at 09:13 AM

    It seems that you have updated your previous question with 

    "I'm not sure how you can apply LAN10 to a Log() function?" 

    LOG(number) = LN(number) / LN10, where LN(number) is the function currently available at Form Calculations widget as log().

    Can you provide the link to your form, so I could be more explicit?

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    mbewley
    Answered on May 09, 2018 at 12:55 PM

    Here is a link to the form. Understand, this form has IF statements for male vs female and whether user knows their body fat percentage or not. So, in order for a MALE USER who DOES NOT know their body fat, field options appear and calculations for body fat are appropriated.

    https://www.jotform.com/build/72976472994174?iak=0dc12d28c679dda6f30ca96d9bad0c6d-2e675f44c1940d9f

    Are you suggesting LAN10 is comparable to LOG10 (10 being a sub)

    MALE

    1525884773male.png

    FEMALE

    1525884797female.png

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    Victoria_K
    Answered on May 09, 2018 at 04:39 PM

    Hello again, 

    I am testing the formula you have shared. Unfortunately, I do not have any results yet, but I am sure that the issue with log() function is resolved. As I suppose there is another incorrectness with Form Calculations widget, I have moved your formula as new thread. I will get back to you soon with the results of my tests here: https://www.jotform.com/answers/1468338