boh8eia se ergasia gia suggrish maple me matlab.

[Pablo_Hasan]

kalhspera, exw mia ergasioula na kanw, na suggrinw tis routines tou paketou ths grammikhs algebras tou maple (Student[LinearAlgebra]) me tis analoges tou matlab, anaforika me ton xrono kai thn akribeia twn apotelesmatwn.

 

profanws prepei na kanw connect to maple me to matlab (with(Matlab), auto pou den mporw na katalabw einai pws mporw na dw ton xrono teleshs mias routine kai pws mporw 8a suggrinw thn akribeia twn apotelesmatwn?

[Pablo_Hasan]

ti egine, kanenas den kserei kapoia entolh sto maple h matlab pou na xronometrei enan upologismo, eite se ms, eite se kuklous tou epe3ergasth... ?

[powerfty]

Sto Matlab mporeis na xrisimopoihseis tin tic me syndiasmo me tin toc gia na metriseis to xrono ektelesis enos block enos programmatos. Thymisou omws pws meta apo mia tic h kathe toc metraei apo tin teleutaia tic. Gia paradeigma des ton katwthi kwdika se Matlab

 

tic

N=100000;

A(1:100000)=0;

for i=1:N,

A(i)=rand;

end

toc

 

Sti Maple (exei perasei kai kamposos kairos pou egrafa se Maple ) mporeis na xrisimopoihseis 2 texnikes oi opoies fainontai ston katwthi kwdika

 

1)

h1:=kernelopts(cputime):

i:=0:

for i from 1 to 1000000 do

i:=i+1:

end do:

kernelopts(cputime)-h1;

 

 

2)

restart:

st := time():

i:=0:

for i from 1 to 1000000 do

i:=i+1:

end do:

time() - st;

 

 

Simeiwsi oloi oi xronoi epistrefontai se seconds.

[Pablo_Hasan]

thanks, polu kalo to tic toc,

mhpws ksereis pws mporw sto matlab na kanw pinakes me stoixeia apo tuxaious akeraious apo mia suggekrimenh ektash. px [-99, 99]

(profanws einai polu eukolo alla exw pelagwsei sta diafora help files pou psaxnw)

[Vangosmech]

pablo για τσέκαρε μήπως είναι με την εντολή rnd(*,*) ή rand(*,*) νομίζω...όπου * οι διαστάσεις που θες...Τώρα δεν είμαι και σίγουρος γιατί έχω να το κάνω απο το 1ο έτος.....;-)

 

Ελπίζω να βοήθησα.....

[Vangosmech]

τελικά είναι rand(*,*)...χρειαζόταν ένα ξεσκόνισμα ;-)

[Pablo_Hasan]

nai ok gia tis diastaseis,alla ta stoixeia tou pinaka einai apo 0 - 1,0. Kserei kaneis pws mporw ta stoixeia na einai tuxaioi akeraioi, apo to -99 ews 99?

[georgemarios]

ο ψευδοκωδικας θα ειναι 99*2*(rand()-0.5) εφοσον ο rand επιστρεφει πραγματικες τιμες μεταξυ 0 και 1

[Pablo_Hasan]

swstos, kai epeidh h8ela akeraious ebala olh thn entolh mesa sto int8()

[Pablo_Hasan]

kserei kaneis pws mporw na kanw export apo to matlab sto maple matrixes, vectors, ktl?

[Geo_2576]

Basika an 8eleis na sugkrineis 2 diaforetika paketa kalo 8a htan oi pinakes na mhn einai rand alla na kataskeuaseis ena pinaka kai ola ta apotelesmata sou na einai basismena panw se auton ton pinaka. Deuteron an den kanw la8os h maple den exei paketo me routines grammikhs algebras alla xrhsimopoiei auto ths matlab.Opws kai h matlab den exei paketo me sumbolika ma8hmatika alla xrhsimopoiei auto ths maple.

[Pablo_Hasan]

ti enneoeis na kataskeuasw? den mporw na kanw enan pinaka px. 120 * 120 me to xeri...

gia to deutero den nomizw oti einai etsi, polles routines tou maple den exei to matlab kai antistrofa, kai mou dinoun kai diaforetikh akribeia se apotelesmata.

[Geo_2576]

Ennow oti kataskeuazeis ena tuxaio pinaka, ton apo8hkeueis kai meta xrhsimopoeis auto ton pinaka gia ola ta peiramata sou.Profanws bgazeis diaforetika apotelesmata giati h matlab xrhsimopoiei ari8mhtikes me8odous epilushs enw h maple pio polu xrhsimopoiei analutikes me8odous epilushs.Gia auto to logo exeis kai diaforetika apotelesmata (ta opoia einai (den 8umamai pws legontai akribws) round errors ).

[Pablo_Hasan]

nai, exw 2 -3 merikous suggekrimenous pinakes pou xrhsimopoiw sta8era se oles tis suggriseis, alla tous kataskeuasa me thn rand giati xreiazomai megales diastaseis, ksereis esu kanenan allo tropo na kataskeuasw megalous pinakes, xwris na xrhsimopoihsw thn rand?

[Geo_2576]

Oxi egw aplws h8ela na sou episthsw thn prosoxh sto na xrhsimopoiseis ton idio pinaka se oles sou tis sugkriseis.