Plotting matrix items
by Michael Boldin

Suppose I have looped through N time series variables and have N slope
coefficients from a simple regression for each dependent variable in a Nx1
matrix.
I now want to show these as y variables in a scatter plot for a given x
variable -- in a different (and already constructed) Nx1 matrix. Can I
easily do this ?
I tricked GRETL to plot 2 new series based on the matrices as so
scalar nn=rows(bx)
smpl 2001:01 2001:01+nn-1
series y= bx
series x= mx
chart1 <- gnuplot y x --with-lines
But I'd rather not trick gretl by creating series, when the matrix values
are not actually time series.
I could export the matrices to a new dataset or export to another plotting
package or even use EXCEL, but I wonder if there is something more elegant
all in GRETL
-- i.e. create a plot directly from the matrices, independent of the
dataset design (ie. time series, cross section, panel) and current smpl
period
PS It took me some time to figure out I could only create the series y=
bx if the smpl was the exact right size -- error message was a little
obtuse. The error: 'The variable y is of type series'
A error message such as 'Can not create series from matrix unless smpl
period agrees with matrix size' would be bettter.
8 years, 8 months

multivariate ANOVA and function cdemean question
by Pindar

Hi there,
I'm trying to do multivariate ANOVA and have a bit trouble with the
following code:
<hansl>
nulldata 8
matrix Y={9,4;10,2;11,0;2,3;4,4;6,5;1,5;5,9}
matrix G={1;1;1;2;2;2;3;3}
matrix T=mcov(Y)*(rows(Y)-1)
eval T
matrix Ns =zeros(rows(uniq(G)),1)
#*How to get to the Sum of squared residuals?*
matrix Y_g1=Y[1:3,]
matrix Y_g2=Y[4:6,]
matrix Y_g3=Y[7:8,]
matrix C={}
matrix C1=mcov(Y_g1)*(rows(Y_g1)-1)
matrix C2=mcov(Y_g2)*(rows(Y_g2)-1)
matrix C3=mcov(Y_g3)*(rows(Y_g3)-1)
matrix C=C1+C2+C3
eval C
matrix C={}
loop for g=1..rows(Ns)
#C+=mcov(Y_g$g)*(rows(Y_g$g)-1)
* C+=C$g* *# this is not working*
endloop
eval C
<hansl>
Up until now I did not find a way to get to know the number of obs per
group or the indices for the the matrices matrix Y_g*.
Should work with some loop construction. However, what do you thing of
giving the function cdemean a second argument that demeans the columns
according to the structure of the groups as in G:
*C=cdemean(Y,G)'cdemean(Y,G)'
*
Cheers
Leon Unger*
*
8 years, 8 months

The Loop Mystery (differences between "loop" and "loop foreach")
by Henrique Andrade

Dear Gretl Community,
I would like to know what is wrong in the
following loops (Case 1 and Case 2):
# Case 1
loop foreach phor 0 1 2 --quiet
loop i = 1..2 --quiet
loop j = phor+1..phor+2 --quiet
scalar TESTE = $j
print TESTE
endloop
endloop
endloop
# Case 2
loop phor = 0..2 --quiet
loop i = 1..2 --quiet
loop j = phor+1..phor+2 --quiet
scalar TESTE = $j
print TESTE
endloop
endloop
endloop
As much as I know, they should present the
same result. Am I wrong?
Best regards,
Henrique Andrade*
*
8 years, 8 months

Qns
by clarodina clarodina

Have some questions
1) does gretl has a online version on a website? R has online version
2) does the ensure uniform sample size on the view-->corr implies using the
least number of sample observations? A variable has 20 sample observations
and B veriable has 26 observations choosing ensure uniform sample size
implies gretl would use the first 20 observation from both variable? what
about there are missing observations in between variable B what would gretl
use?
8 years, 8 months