Combine 2 graphs?

[marco1992chung]

I have to create a buffer titration curve with 2 set of data
how can i combine graph A&B to get Graph C?


Problem.xlsx

[darknation144]

Do you want them to over lap?

[marco1992chung]

I wanna connect them to form a single line graph
is it possible?

[MrShorty]

As many titration curves as I've plotted, I have to believe that it is possible. Unfortunately, I can't download your sample file, so I can't see what you are starting with.

I'm guessing you are starting with 2 tables, corresponding to the two titration curves. Usually the easiest way I find to combine two plots is to build a third table that appends the 2nd data set onto the first data set, then use this third table to build the graph.

[darknation144]

The download does work.

[marco1992chung]

Can you download these attachments?
Graph A.jpgProblem.xlsGraph B.jpgGraph C.jpg

[Andy Pope]

Plot 2 series as xy-scatter rather than line

You will need to alter the x-values to be negative.

[marco1992chung]

Thanks for your help Andy, this is the graph I wanted.
but there is a big problem, my x-axis is the no. of ml of chemical added which can never be negative values
so is it possible not to alter the x-values to obtain this graph?

and i have a follow-up question. Can I set up some dotted lines as shown in the attachment to find the corresponding x,y values?
Problem 2.jpg

[MrShorty]

I would agree with Andy to use a scatter plot. However, since both data sets start at 0, it won't be possible to plot them like you want without modifying the x values for at least one of the sets. It looks like one titration was performed by adding an acid, the other was performed by adding a base. Since the data is "starting" in the "middle" and working out to both ends, Andy's idea of making one set negative makes sense to me. If you prefer to not to have negative values, then you'll need to modify the x-data so that the final data set looks more like someone started at one end and titrated through the other. Shouldn't be any more difficult than an addition function.

Usually when I set up those kind of "crosshairs" to locate a point on the graph, I will usually simply plot an additional series with three points:
0 y
x y
x 0

Link the x and y cells to a couple of cells where I can manually enter x and y, and the crosshairs can be put wherever I want them.

[jpr73]

Hi,
See attached in base of Andy's file, the interpolate points to draw the lines recall of abscissa and ordinate for negative and positive axis values
Best regards

[marco1992chung]

Thanks all of you =] my problems have nearly solved
I ve opened jpr73's attached .xlsx but i cannot figure out the step to draw the interpolation line?
Can anyone show me?

[jpr73]

Hi,
On sheet1, see the 2 tables at C35 to D43
The left side table is for drawing the line recall x and y of serie2 : value <= 0
The right side table is for drawing the line recall x and y of serie1 : value >= 0
Column C contain x values and column D contain y values
With a given x value in C38 and C43, calculate the intersection point to the curve in D38 and D43 with the interpolate function
In order to draw horizontal and vertical line, complete the table with each coordinates
Add 2 news series to the chart : left side and right side
Add a secondary y axis to draw the y line recall to the right side for value >=0
Format the new serie and add labels
Hope this procedure helps
Best regards

[Andy Pope]

You can use original data if you use secondary axes.
The secondary horizontal axis will need to be in reverse in order to make the line go from right to left of zero.

The negative scale values can be removed by using custom number format.