semi log graphs

[Guest]

I am interested in making Semi-log graphs with the X axis having the log
scale. I understand that this can be done in XY scatter.

My x-axis values range from .002 to .312
Do i still need to format my X-axis with a MAX of 10?
Is there a method to set the minor units on my X-axis to smaller increments
? (i.e. .001)

Can I zoom in on my graph in my area of interest if i use a MAX 10 x axis?

Does the Trendline equation, slope and intercept formulas used with linear
graphs function with semilog graphs? With linear graphs i made a standard
curve with known x and y values and then input the y value of an unknown and
solved for x using the trendline equation. Does this work with semi-log?

Semi log challenged,
dr chuck

 

[Guest]

I think i actually have the graph functioning appropriatly.
I used log trendlines in my graph.
I guess my prime concern at present is if the trendline eqaution, slope
equation and x and y intercepts from excel that are used with linear graphs
also work with semi log graphs or if i need to modify the formula?

 

[Guest]

sorry to keep updating.
under trendline format i found where i could make excel display the equation.

The example below is a semilog trendline equation.
y = 0.8065Ln(x) + 3.4412

I am not sure if i am supposed to enter a number in for the " Ln" of if
that is just a some kind of notation to indicate that it is a log number?

 

[David Biddulph]

If you let the x axis auto-scale when you've applied the log scale, it will
set the minimum to .001 and the maximum to 1. The increment is a factor of
10, so the points on the axis are 0.001, 0.01, 0.1, and 1. I don't think
you can get the increment smaller than a factor of 10.