Logarithmic Trendline

I am testing out iWork '09, hoping to get away from Office. So, naturally, I'm importing a few of my Office documents (Word docs and Excel spreadsheets so far) to see what happens. I've run into a problem with Numbers and hope someone can help. This problem isn't about an import issue, it seems to be a problem with trendlines in Numbers.
I have created a scatter chart with a logarithmic X axis, linear Y axis, and a logarithmic trendline. A log trendline on this chart should be a straight line. The trendline equation is correct and I can create and plot a second series using the equation but the trendline plotted by Numbers is nowhere near correct. The trendline is plotted as if the X axis is a linear scale, which it is not. In fact, if I change X to a linear scale, the trendline looks exactly the same as before (but is now correct).
Any ideas, am I doing something wrong?

For the original problem, it is easy to create a simple 5 datapoint logarithmic chart with a trendline by just making up some numbers. I can't send you my data because it is company proprietary. I put in feedback to Apple, I'm sure a bug report will go in soon from someone else with the same problem. I think I'll drop it at this time. I can do without the trendline plots for a while as long as I can get the equations (which seem to be correct).
On the issue of trendlines being non-equivalent when swapping the X and Y axis, that is not a bug so no action is required.
Thanks.

Similar Messages

Adding a Logarithmic Trendline to an X-Y Graph

In my VI I am taking measurements from a DAQ, calculating phase shift and frequency and writing it to a TDMS file.
After I have this TDMS file I want to make a scatter plot of the data on an X-Y graph with a logarithmic trend line. I am plotting phase shift (Untitled 1) versus frequency (Untitled). I succeeded in graphing the data, but I am having trouble adding the trendline. I have attached the VI in question. I tried to attach the TDMS file, but the forum does not allow such attachments.
Thanks for any help or suggestions that you can offer.
Attachments:
Research- Voltage.vi ‏459 KB

Hi,
I had a little look over the relevant part of your vi. The log fit function returns an array of y values, so you can plot these against x, and add it to your graph alongside the actual values.
One way to do it using the functions you've implemented is like this:
See if this works.
One extra thing that might be helpful, you don't have to open the TDMS file twice, you can just open it once then do as much reading as you want, then close it once. (you can read multiple channels at once too, using an string array as the channel name input to the TDMS read.
All the best,
Ian S
Applications Engineer CLD
National Instruments UK&Ireland

Trendline in Legend?

Post Author: vjromeo
CA Forum: Charts and Graphs
Is it not possible in Crystal XI to have an entry in the chart legend for a trendline? I have charts that have been done in Excel, that we'd like to move to Crystal, which include multiple trendlines for various series, and at times legend entries are important to be able to tell on what series a trendline is based.

Not exactly sure if this will work for CR XI, but in later versions of CR you have to select the series in the graph which you would like to create a trendline on and change it to be the trendline.
Therefore, click on the series in the graph that you would like to become the trendline. (Make sure the series is highlighted before right-clicking on the highlighted section) Right-click on the highlighted series, and then select "Trendlines".
You will then get an option to select the type of trendline to use. Once selected, the trendline will be created and applied in the graph.

Crystal Report Chart Problem: No trendlines with regression

Hi,
I have a severe problem with chart trendlines in Crystal Reports 2008 (12.3.0.601).
Trendlines with regression do not work, whereas average and moving average work on charts with data axis but not with numerical axis.
Does anyone has an idea, how to solve it.
Best regards
Michael

hi,
Try to create a bar chart with Year, Quarter as dimensions and Sales revenue as measure.
Now your chart has legend which shows quarter values.
Right Click the Legend value Q1 -> Series Options -> Trendline.
Choose the required regression type: Linear/ Polynomial/ Logarthmic/ exponential/ Moving Average.
This will show the required trend line.
Regards,
Vamsee

Can a trendline in Numbers be extended to see predictions without adding data that does not exist?

The spread sheet that I'm working with adds daily data over a 6 month timeframe. The trendline stops at the newest data point. I would like to know what to expect in 6 months so I can make adjustments to adjust progress. I would like to do this without adding false data that I don't have yet.
Thanks

If you notice in my first response... the top screenshot shows a plot with a trend line that shows the equation. I used the slope and offset in the formula that extend the "prediction"
you could use the forecast() or linest() function to create this prediction with out the trend line.
Here is another example:
I entered actual (but made up) data in columns A and B
then I calculate the slope and intercept of that data in column F
F3=INDEX(LINEST(B2:B6,A2:A6,TRUE,TRUE), 1)
F4=INDEX(LINEST(B2:B6,A2:A6,TRUE,TRUE), 2)
now in columns C and D I enter X values and calculate predicted Y values using the slope and intercepts:
D2=$F$3×C2+$F$4
select D2 and fill down as needed

How to Make a Line of Best Fit/Best Fit Line/Trendline in iWork Numbers '09

I'm not sure if this is well-known or has been answered elsewhere already, but multiple Google searches have not shown this solution on how to create a line of best fit in Numbers '09 (there is another method that involves drawing a line yourself, but this is much easier and more accurate).
I stumbled across this trying the above self-draw technique and got so excited I wanted to post the technique. So here is what you do:
1) Type out your X and Y data
2) Select the data and select Charts, then select the Scatter Plot
3) Open up Inspector and select the Chart tab
4) Select the "Series" tab below the picture of the Scatter Plot and the "Chart Colors..." button
5) At the bottom of the Inspector window, open the "Advanced" arrow
6) Select the "Trendline" tab and select the "Linear" trendline from the drop-down bar
That's it! You can even select the options to show the line equation or the R-squared value!
Here is a picture of the selected options and what your graph should look like (check that nice R-squared value!).
http://i.imgur.com/AvfPv.png
I hope this helps and hope it moves up to the top of the Google search page for this feature.

Hi Asclepius37,
Why not just search "trend" or "trendline" in the Numbers '09 User Guide?
That would take you to page 149 of the guide and the article "Showing Trendlines in Charts," which lists a set of instructions very similar to those in your post.
The Numbers '09 User Guide and the iWork Formulas and Functions User Guide are searchable pdf files, and may both be downloaded through kinks in the Help menu in Numbers. Both are excellent resources to have on hand.
Regards,
Barry
PS: Searching "best fit" will return zero results, but "best" or "best-fit" will get you to the same article.
B

What statistical methodology is used to create a trendline in numbers

I am doing a paper and have a trendline generated by Numbers on a scatter plot, and would like to avoid confirming my 'm' and 'b' values with a least squares calculation. Does anybody know what methodology is used in the algorithm that calculates trendlines in numbers so I can report that rather than doing the calculation myself?

Hi Michael,
It's really surprising what one can learn by reading the documentation supplied by Apple.
A search of the iWork Formulas and Functions User Guide using 'least squares' as the search term brings up two hits, both describing the LINEST function.
The same search in the Numbers '09 User Guide returns no results, but a search on 'trendline' returns many, with most occuring on two consecutive pages. Clicking one of these brings up the article Showing Trendlines in Charts, which doesn't directly mention "least squares", but does imply that method in the following note (emphasis added):
To see the R-squared value that was used to calculate a trendline, select the line, and then select Show R^2 Value. You can drag this number to wherever you want it to appear on the sheet.
Both these invaluable user guides are available for download via the Help menu in Numbers '09.
Regards,
Barry

Is there any way of extending a polynomial trendline in Numbers '09?

Hi,
The question title says it all really. Is there any way of extending a polynomial trendline in Numbers '09, beyond the data that I currently have? I can do this in Excel, but would like to be able to do this in Numbers too.
Thanks,
Nick

Unfortunately there is no "forecast" feature for trendlines in Numbers. Wayne showed how to use the trendline equation from the chart to create additional data points for the chart. This is by far the simplest way to do it in Numbers but it has two drawbacks:
If your data changes, you'll need to manually readjust the coefficients for your forecasted point(s).
The precision of the coefficients is only three decimal places. The forecasted Y values using these coefficients might not be as accurate as you would like. For example, compare the forecasted Y value in Wayne's table at X=20 to the one in the table below.
You can avoid both problems by calculating the trendline coefficients in your table using the LINEST function. it is a little more work in the setup but it might save you time in the long run if your data changes a lot. Here is an example of for 2nd order polynomial:
The last "real" data point is in row 10.
Formula for column D =A
Formula for column E =A*A
F2 = the coefficient for X^2 =INDEX(LINEST(B2:B10,D2:E10),1)
G2 = the coefficient for X =INDEX(LINEST(B2:B10,D2:E10),2)
H2 = the constant =INDEX(LINEST(B2:B10,D2:E10),3)
Note: If you later need to add an additional data point at the end of your data, go to the last row of your data (in this example it is row 10) and "add row below". This way the formulas for the coefficients will adjust automatically to include the new row.

How do I add a trendline in numbers for iPad?

I want to add a trendline to a 2D scatter chart in numbers on my iPad Air. Can anyone help me with this?

if you want to add a linear best fit line you can get the parameters for that line from your existing data and make a NEW series:
Using my previous charts you can add a new table (in this case below the chart) used to calculate the slope (m) and the y-intercept (b) for each of the original series. Then you can use those two values with the original X values to construct a best fit line. The bottom table is named "Best Fit Constants" and is constructed:
B1=INDEX(LINEST(Data :: C,Data :: B,TRUE), 2)
B2=INDEX(LINEST(Data :: C,Data :: B,TRUE), 1)
D1=INDEX(LINEST(Data :: E,Data :: D,TRUE), 2)
D2=INDEX(LINEST(Data :: E,Data :: D,TRUE), 1)
The original table (which I named "Data") is constructed as follows:
F2=B2
G2=Best Fit Constants :: $B$1+Best Fit Constants :: $B$2*F2
H2=D2
I2=Best Fit Constants :: $D$1+Best Fit Constants :: $D$2*H2
select F2 thru I2 and fill down as needed. Expand the graph range by selecting the chart,
then dragging the data range controls (in the table) to include the best fit data

Adding trendline in Numbers for iPad

Can I add trendlines for my charts in Numbers for iPad?

Don't type the two letters "nu" but the three "ios" ones.
You will get two entries :
iMovie for iOS
and
iWork for iOS (which is ridiculous because this product doesn't exist).
Clicking on this late entry you will enter a community grouping questions upon the three apps.
Click the button "Refine this list" to restrict to Numbers.
I already asked the forum staff to change this odd behavior so that
typing nu offer Numbers 4 iOS
as well as Numbers 4 mac OS
And of course, same request for Keynote and Pages.
Wait and see.
Yvan KOENIG (VALLAURIS, France) samedi 25 juin 2011 12:08:36
iMac 21”5, i7, 2.8 GHz, 4 Gbytes, 1 Tbytes, mac OS X 10.6.7
Please : Search for questions similar to your own before submitting them to the community
To be the AW6 successor, iWork MUST integrate a TRUE DB, not a list organizer !

Creating trendline in labview graph

Hi,
does anyone know whether is it possible to create a trendline in labview's graph?
kinda like in excel u can create a trendline but i want to do it in labview, is it possible?

You can use the curve fitting functions to find a curve to fit the graph and then add it as a plot to the graph. Examples ship with LabVIEW on using the fit functions and on creating multiple plots for graphs.

Trendline in Scatter plot

Hi,
I have a couple question on Power View 2010
1. I want to know if I can plot regression Trendlines(Linear/polynomial/power) on scatter plot?
2. Navigation between pages- Is it possible to navigate between report pages in Power View 2010 by passing parameters from the first page to the next page?
3. I have a report that has 3 pages. I want to create 2 pages in SSRS 2012 and one in Power View 2010. Is it possible to navigate between these applications and also pass parameters in the URL?
Thanks in advance.
Ankit

The reason why it hangs is because you have 2 event structures inside a loop. You should only have one event structure in a loop. This is documented in the LabVIEW Help. With 2 event structures one of them will block the other.
Your code is also about 3 times larger than it needs to be:
To create the array of names for the dropdowns you only need to autoindex a for-loop from the 2D array of data and use the Format Into String function. You don't actually need to use the values - you only need to autoindex the for-loop.
Using Delete From Array and Reshape Array just to pull out a row is simply silly (not to mention a Rube Goldberg). That's what Index Array is for.
In the Cursor Move event case you only need one function: Index Array. The point index is already available to you from the event case's data.
Half of the code really belongs outside of the while loop since none of that data ever changes, so what's the point of regenerating it each time?
Instead of using 2 Index Array functions just to get the list of names, wire a True to the Read From Spreadsheet File's transpose? input and use the first row output.
I've attached a simplified version of your VI.
Attachments:
PCoption2_MOD.vi ‏34 KB

Trendline in graphic

Hi,
I'm using Crystal Reports XI, I create a graphic in my report and I want to have a trendline in this graphic.
I look on the Internet and the helpfile but I didn't find a way to do it.
It is possible ?
Regards,
Hugo

Not exactly sure if this will work for CR XI, but in later versions of CR you have to select the series in the graph which you would like to create a trendline on and change it to be the trendline.
Therefore, click on the series in the graph that you would like to become the trendline. (Make sure the series is highlighted before right-clicking on the highlighted section) Right-click on the highlighted series, and then select "Trendlines".
You will then get an option to select the type of trendline to use. Once selected, the trendline will be created and applied in the graph.

Is there a way to logarithmically stretch 4x3 to 16x9 in FCP?

Hi everyone-
I have recently re-telecined a 16mm film so I could get it as an HD master. it was originally shot and composed in 4:3 years ago.
HD is 16:9. The 16mm film, as I said, is 4:3. I am trying to find a way of changing the aspect ratio. I know I can simply strectch the horizontal, but then all the people are short and fat. I could zoom so the sides hit the edge of frame, but then I loose a lot of head room.
When I have played the 4:3 DVD on my 16:9 Panasonic TV there's a mode called "just" (I have seem simillar modes on other brands called "mesh"). It zooms in the image slightly and streches it logarithmically. The center of the image is virtually untouched. The sides are gradually further and further stretched as it moves further from the center.
Sure, some shots look odd (if a person walks from left to right of frame they will go from long and flat on one end to normal shaped as they go through the middle of the picture space to long and flat on the other end. But for 99% of the DVDs I have watched (and the over the air Standard def stuff) the method looks fantastic.
I think combining the three various methods on a shot by shot basis would be the best solution.
The problem is I haven't been able to find a way to do that "logarithmic stretching" on FCP. Has anyone here seen a way? Or is there a plug in that I can buy? Its seems like it should be a simple math based solution.
Thanks much,
David
Quad core 2.5 GHz G5, 8 GB Ram, NVIDIA 7800 GT and ATI X1900 Mac OS X (10.4.9)

I tried the "Too Much Too Soon Free Plugins" filters. The smart strech does do what it says, the big issue with it, is it has a very noticable line where the streching occurs. It's not a gradual stretch. In other words if you have a close up of a person, the center part of the screen is great. Unstretched. However, there's a soft fuzzy line about 2/3 of the way into the screen where suddenly it is completely stretched from there to the edge of the picture. Obvioulsy when the person (or camera) moves you can quite clearly see where the line is.
In effect, it kind of looks like what would happen if I took a 4x3 image on V2, did a soft crop of a few inches off the sides. Then on V1, took the same image and stretched it to fill a 16x9 frame. Then, matched where the soft crop line was.
I looked to see if I could either make the line softer (and less noticable) or even change where the "line" was. Unfortunately, it was a no on both counts... In fact, there are no user customizable options at all with the filter
Any other suggestions?
Thanks,
Dave

Make trendline thicker on scatter plot?

My trendline or more specifically just the line connecting my points on my scatter plot is blue and skinny. How can I increase the thickness?

See below:
Change colour and thickness of the line/curve connecting data points:
Select the chart by clicking its icon in theSheets list in the sidebar.
Click the square in the tab indicated,
Use the stroke controls indicated to change the thickness of the line (and its colour).
To change colour and thickness of the trend line:
Click the trend line to select it.
Use the stroke controls as above. The controls will appear toward the left end of the Format bar in this case, but will function in the same manner.
In the diagram, the trend line has been set to 2 pts and a teal/turquoise colour; the connecting curve between data points has been set to 7 pts and a darker blue.
Regards,
Barry

Logarithmic Trendline

Similar Messages

Maybe you are looking for