I have an issue running a certain script in octave.
This is the code that produces the error:
#germanium
T=410:20:600;
x=linspace(400,410,100);
y=linspace(10^9,10^9,100);
k=8.5*10 .^(-5);
Eg=0.59;
Nc300=1.02*10^13;
Nc=Nc300*((T/300).^(3/2));
n=Nc*(e.^(-Eg/(2*k*T)));
plot(T,n,x,y,'m');
grid on
xlabel('Temprature');
ylabel('Electron Density n');
title('Germanium n(T)');
As mentioned in the Title, the error that is produced is the following:
error: ger5: operator /: nonconformant arguments (op1 is 1x1, op2 is 1x10)
I have done a lot of testing, and I figured that the problem originates from the T variable on the 9th line : n=Nc*(e.^(-Eg/(2*k*T)));
The codes run fine without it. For example :
#germanium
T=410:20:600;
x=linspace(400,410,100);
y=linspace(10^9,10^9,100);
k=8.5*10 .^(-5);
Eg=0.59;
Nc300=1.02*10^13;
Nc=Nc300*((T/300).^(3/2));
n=Nc*(e.^(-Eg/(2*k*500)));
plot(T,n,x,y,'m');
grid on
xlabel('Temprature');
ylabel('Electron Density n');
title('Germanium n(T)');
In which case I simply replaced T with 500 , the code runs perfectly fine.
Sadly T, can not be replaced by a certain number since it is the variable used in my graph. Although I did some digging, I never managed to fully understand this error, or how to fix it, thus any help would be greatly appreciated.
Thanks.
Add a . before your *, /, and ^ signs. This will ensure that octave uses scalar multiplication instead of matrix multiplication.
n=Nc.*(e.^(-Eg./(2.*k.*T)));
Related
In normal situation, we can use ";" to show the next answer if there is one.
But if I do this, it shows me
error: char_code/2: Cannot represent due to 'character_code'
In stead of ";", I use "shift + ;", and prolog gives me a prompt
Unknown action: : (h for help) Action?
then if I input ";", the designable answers will be shown one by one.
What is the problem?
Use swipl-win.exe instead of swipl.exe can solve this problem.(I tried 6.x and 7.x)
By the way, swipl works well under MacOS.
I'm trying to solve a water, jug problem (one 7L, one 4L, get 5L in the 7L jug) using dept first search. However something keeps going wrong whenever I try to get a new state back from one of my actions.
Prolog Code
I can't figure out what is going wrong, this is what the output looks like after trace:
enter image description here
Thanks in advance for any help!
You should copy and paste your code into your question; we cannot copy and paste it from your images, which makes it more work to help you, which in turn makes it less likely that we will help.
Some problems I noticed anyway:
Your first rule for go_to_goal/3 does not talk about the relation between ClosedList and Path. You will compute the path but will never be able to communicate it to the caller. (Then again, you also ignore Path in solve/0...) If your Prolog system gives you "singleton variable" warnings, you should never ignore them!
You are using the == operator wrong. The goal State == (5, X) states that at the end you are looking for a pair where the first component is 5 (this part is fine) and the second component is an unbound variable. In fact, after your computations, the second component of the pair will be bound to some arithmetic term. This comparison will always fail. You should use the = (unification) operator instead. == is only used rarely, in particular situations.
If you put a term like X+Y-7 into the head of a rule, it will not be evaluated to a number. If you want it to be evaluated to a number, you must use is/2 in the body of your rules.
Your most immediate problem, however, is the following (visible from the trace you posted): The second clause of go_to_goal/3 tries to call action/2 with a pair (0, 0) as the first argument. This always fails because the first argument of every clause of action/2 is a term state(X, Y). If you change this to state(0, 0) in go_to_goal/3, you should be able to make a little bit of progress.
I am trying to run this prolog code in DrRacket: http://www.anselm.edu/homepage/mmalita/culpro/graf1.html
#lang datalog
arc(a,b).
arc(b,c).
arc(a,c).
arc(a,d).
arc(b,e).
arc(e,f).
arc(b,f).
arc(f,g).
pathall(X,X,[]).
pathall(X,Y,[X,Z|L]):- arc(X,Z),pathall(Z,Y,L). % error on this line;
pathall(a,g)?
However, it is giving following error:
read: expected a `]' to close `['
I suspect '|' symbol is not being read as head-tail separator of the list. Additionally, [] is also giving error (if subsequent line is removed):
#%app: missing procedure expression;
probably originally (), which is an illegal empty application in: (#%app)
How can these be corrected so that the code works and searches for paths between a and g ?
The Datalog module in DrRacket is not an implementation of Prolog, and the syntax that you have used is not allowed (see the manual for the syntax allowed).
In particular terms cannot be data structures like lists ([]). To run a program like that of above you need a Prolog interpreter with data structures.
What you can do is define for instance a predicate path, like in the example that you have linked:
path(X,Y):- arc(X,Y).
path(X,Y):- arc(X,Z),path(Z,Y).
and, for instance, ask if a path exists or not, as in:
path(a,g)?
or print all the paths to a certain node with
path(X,g)?
etc.
I found this inequality solving program from some Internet source.It works well.This is the program.
:-use_module(library(clpq)).
dec_inc(Left,Right):-
copy_term(Left-Right,CopyLeft-CopyRight).
tell_cs(CopyLeft).
max(CopyRight,Right,Leq).
tell_cs(Leq).
max([],[],[]).
max([E=<_|Ps],[_=<P1|P1s],[K=<P1|Ls]):-
sup(E,K),
max(Ps,P1s,Ls).
tell_cs([]).
tell_cs([C|Cs]):-
{C},
tell_cs(Cs).
The problem I have regarding this program is when I run the program using capital letter variable it works.But it doesn't work for simple letter variables.
This is the syntax i used to solve this problem.
eg:-
{2*X+3>=5}.
This works and gives the correct answer.
{2*x+3>=5}.
When i run this, Prolog says
ERROR: Unhandled exception: nf(y,_G3082): argument 1 must be a a numeric expression
I'm using SWI-Prolog version 6.6.0.What is the problem here and how can I solve it.
I am having a little problem here. In the code below is a function that has two arguments when I attempt to execute the functions i obtained this error
Undefined function or method for input
arguments of type 'double' (X,CX) as shown in (1).
the function is coded as below
[CX,sse]= (vgg_kmiter(X, CX)) ....(1)
can someone point me out where is the problem with this code?
note that the x is the input points in a columns which is integer and the CX is the center of clustering which is also integer.
Thank you
[CX,sse]= (vgg_kmiter(X, CX)) ....(1)
Is not a valid line of code.
[CX,sse]= (vgg_kmiter(X, CX));
is fine, though the outer parentheses aren't needed.
[CX,sse]= (vgg_kmiter(X, CX)) %....(1)
is fine as well - everything after the % sign is considered a comment