## How to extract two or three columns from an XLSM f...

I attempt to get two (or better, three) datas from an XLSM file. The tools doesn't work. I want then to do some tests about the apparied datas extracted.

Could you help me ? The best I did was getting a matrix result from an XLS (and not XLSM) file, and I don't know what to do with this kind of result, as I want only test some hypothesis as a linear regression with or without least squares, not do learn what to do with this matrix result..

Thx to you,

Milos

## Error using NonlinearFit function...

Howdy all,

I am trying to fit an exponential and logistical model to a set of population data i've been given using the NonlinearFit function in the statistics toolbox. When try to find the fit for the exponential function I get an error saying "SVD of estimated Jacobian could not be computed". Furthermore, when I display the regression over the set of data points all it shows is a horizontal line. I'm not sure how to go about fixing this. My data set is only 17 points and my input function is about as simple as it gets.

When I run the program to solve for logisitcal model I do not get the error but the displayed plot still shows just a horizontal line dispite the function being non-linear.

So far I have...

regE := NonlinearFit(a*exp(b*x),year,population,x)

regLog := NonlinearFit(a/(1+b*exp(-c*x)),year,population,x)

expon := plot((regE), x = 1850..2020):

logi := plot((regLog), x = 1850..2020):

display({data,logi,expon});

I have not tried using optimization yet but I will soon although I'm not sure if it will improve my results since my undertanding is that they both use the same process to estimate the parameters.

Anyways, Thanks for the help in advance!!

EDIT: Here is the data I am using.

year := [1850,1860,1870,1880,1890,1900,1910,1920,1930,1940,1950,1960,1970,1980,1990,2000,2010]:

population :=[4668,9070,17375,27985,37249,63786,115693,186667,359328,528961,806701,1243158,1741912,2049527,2818199,3400578,4092459]:

## ScatterPlot with Regression Line...

I imported data into maple from excel.  I was able to make a scatterplot with my data and a regression line, but I have been unsuccessful in trying to combine them both onto the same plot.  I tried multiple different ways but still could not get it to work.

I think it has to do something with the brackets around each element inside my imported array, but I am not sure.  Any ideas would be nice.

My objective is to put the regression line and scatterplot on same graph.project1.mwproject1.mw

Thanks much.

Matt

## Nonlinear regression...

Hello everybody,

I have an nx2 matrix of (t,w) , I need to fit a curve of the form of w = A(t-b)c to the data. What I have already tried is to pick a value for b, then regress log w on log (t-b) linearly, which is not very accurate. I'd  greatly appreciate any comments that could help me to find the optimum values for A, b and c through regression methods.

Thanks a lot,

Haley

## Generalized Least Squares...

Hi Everyone

Is there a built-in way to fit a regression using generalized least squares in Maple ?

## regressions should be fixed within versions 16.03

Maple

If there is a regression in an update it should be fixed within the same version and not left as an open bug in current versions.

Since 16.01 update is no longer available and 16.02 is the only option.  It would be very much appreciated by the mapleprimes community and maple users to see a 16.03 update.

## How to write a procedure for Linear Regression...

Hi,

I know all the necessary computational steps to create a Linear Regression line, but I am having trouble making it into a succient procedure. I have to make a 3 procedures for three methods, minimizing Vertical distance, Horizontal, and lastly, Diagonal.

I uploaded an example of my work to compute a linear regression line, minizming vertical distance. I have all the necessary steps for horizontal and diaganol as well.

## Standard errors in LinearFit...

Hello,

I'm trying to fit some of my research data to a polynomial.   I can do this, but what I need to know is how Maple is calculating the standard errors.  In other words. I need to know the underlying forumla Maple is using for these standard errors.

Is there any documentation on this anywhere?

For reference, the Maple command I am using is:
LinearFit([Z^(-2),Z^(-3),Z^(-4),Z^(-5),Z^(-6),Z^(-7),Z^(-8),Z^(-9)],X,P2,Z,output=standarderrors);

What justifies the t-1; to achieve this result?

restart;
interface(warnlevel = 0, imaginaryunit = I, rtablesize = 12);
with(plots); with(plottools);
alias(FFT = DiscreteTransforms[FourierTransform], IFFT = DiscreteTransforms[InverseFourierTransform]);

Temp := [24.2, 28.4, 32.7, 39.7, 47.0, 53.0, 56.0, 55.0, 49.4, 42.2, 32.0, 27.1];
POI := seq([n, Temp[n]], n = 1 .. 12);

p1 := pointplot([POI], labels = ["x~month", "y = Temperature~ºF"...

## Geometric interpretation of correlation and regres...

by: Maple

I was introduced to the geometric interpretation of correlation and linear regression recently.

Orignially due to the famous statistician R.A.Fisher, the idea is that the correlation between
two variables is the cosine of the angle between the 2 vectors in n-dimensional space.
This can be demonstrated in Maple as follows:

First, we represent each variable as a vector and transform it so that it is centred at its
mean and has a length equal...