Error Bars Log Scale Excel
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April 21st, 2008, 04:45 AM #1 gstuart Newbie Joined: Apr 2008 Posts: 3 Thanks: 0 Error bars on log-transformed plots? Hello - I excel chart error bars am a genetics researcher. I have a series of data points with errors
Excel Chart Error Bars 2010
(standard errors), that I wish to plot as a column plot with error bars: GENE, AVG FOLD CHANGE, SE excel chart error bars 2013 Gene1, 2193.10, 1200.74 Gene2, 96.28, 9.08 Gene3, 39.02, 22.51 Gene4, 5.88, 0.82 Gene5, -0.68, 0.33 Gene6, 1.14, 0.02 Gene7, -1.46, 0.16 Gene8, -1.56, 0.50 Gene9, -1.58, 0.10 Gene10, -1.88, 0.45 Gene11, how to insert error bars in excel mac -2.04, 0.45 Gene12, -6828.82, 975.41 Positive values are up-regulated genes; negative values are down-regulated genes (re: gene expression levels). I wish to plot this as a column plot on a log scale (y-axis) with negative values below the zero baseline, positive values above, and with the errors indicated. Something like: 1000 100 10 * 1 * 0------------------- -1 * -10 * -100 -1000
How To Put Error Bars In Excel Mac
but with bars instead of the asterisks - you get the idea. I can do this easily enough using MS Excel, by taking the log of the absolute value, multiplying the result by +1 or -1 (to restore the original "directionality" - i.e. up- or down-regulated). A couple of questions: (Q1) Is it "better" to use log (base 10) or ln (natural) log transformations? (Q2) How would I present the error bars - would I log (or ln) -transform the standard errors, for example, and plot these [or the absolute values of these, since the log of numbers <1 are negative; e.g. log(0.5) = -0.301)]? I tried finding the answer to these questions in Google, but I wasn't very successful. ... I would very much appreciate any comments regarding the log-transformation of data and plots of log-transformed data, particularly regarding error bars! Thank you! Sincerely, Greg :-) April 22nd, 2008, 01:06 PM #2 gstuart Newbie Joined: Apr 2008 Posts: 3 Thanks: 0 Hello - I think I have this right ... Referring to the sample data (below; this would be easier, if I cou
graphs can give a concise and compact form of representation, while graphs made poorly can be misleading and very confusing. Why use logarithmical graphs? If you find yourself with data spread on an extremely large area, the graph will be very compact and vertical error bars in excel you may miss some sharp drops in values because of this. A semi-logarithmical graph is has how to add standard deviation bars in excel one of the two axes (usually the abscissa) in a logarithmical form. The logarithmical base is usually 10, but can also be “e” or
Logarithmic Error Propagation
any other base. Well let's suppose you have the following table: X 1 2 5 10 20 50 100 200 500 1000 2000 Y 1 2 4 16 256 65536 4.29E+09 1.84E+19 3.4E+38 1.16E+77 1.3E+154 The corresponding Excel scatter chart http://mymathforum.com/algebra/2903-error-bars-log-transformed-plots.html is this: On the other hand, if you extract the logarithm of both X and Y rows you get this table: log_x 0 0.3 0.7 1 1.3 1.7 2 2.3 2.7 3 3.3 log_y 0 0.3 0.6 1.2 2.41 4.82 9.63 19.27 38.53 77.06 154.13 And its corresponding graph: Does it make sense now? I thought so How to obtain the logarithmic graph Double click the axis that you want to be on a logarithmical scale. In the "Scale" http://bubble.ro/Logarithmic_scale_graphs_in_Excel.html tab, select the "Logarithmical Scale" option and click ok. Then, go to the Chart Options (in the Chart menu) and in the "Gridlines" tab check the "Minor gridlines" on the axes you want depending of the desired graph type: semi-logarithmical or logarithmical. That's it ! Hope this helps ! » Permalink Posted by: Nitro on March 18, 2006 at 14:51. » Comments Har har Very interesting. I never thought logarithmic scales would lighten up my life ;)... Posted by SunBeam on March 20, 2006 at 05:19 PM. Tip Just remember to use the normal values when you select source for the graphic, Excel does the log operation for you. Posted by Mika on March 21, 2006 at 01:18 AM. Hello, sort anoob here hello ladies and gents! I've been kind of lurking around. I love this site! thanks for having me :) Posted by Nanbe1st on October 16, 2006 at 06:49 AM. thanks you just made my day thanks so much for your help i was able to find this site on the 1st page of google assignment done! :D Posted by mr.mackey on January 24, 2007 at 02:17 AM. Y crossing point How can I have the Y axis cross the X axis at its MINIMAL value (X axis being logarithmic)? Thanks in advance Posted by anne on March 5, 2007 at 11:06 AM. Limitations of logarithmic graphs in Excel Unfortunately Excel is only abl
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