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Hints for Efficient Balisc/Scilab 6.x Coding

• Use type instead of typeof, whenever possible.
• Use nargin, nargout instead of argn.
• Use x==[] instead of isempty(x), whenever possible.
• Use x<>[] instead of ~isempty(x), whenever possible.
• Use issquare instead of size, whenever possible.
• Use length(x) instead of size(x,'*'), whenever possible.
• Use x(length(x)) or x(size(x,'*') instead of x($), whenever possible.
• Use &&, || instead of &, |, whenever possible.
• Use ~(A || B) instead of ~A && ~B (cf. De Morgan's Laws).
• Use ~(A && B) instead of ~A || ~B (cf. De Morgan's Laws).
• Use execstr instead of evstr, whenever possible.
• Use tokens instead of strsplit, whenever possible.
• Use matrix(A,length(A),1) instead of A(:), whenever possible.
• Use A.B instead of A("B") or getfield("B",A), whenever possible.
• Use ones(m,n).*.A instead of repmat(A,m,n), whenever possible.
• Use size(x)==1 instead of isscalar(x) or size(x,'*')==1, whenever possible.
• Use A=[] instead of A(:)=[], whenever possible.
• Use .* and ./ instead * of / for integer types, whenever possible.
• Use a & b instead of bitand(a,b), whenever possible.
• Use a | b instead of bitor(a,b), whenever possible.
• Use (a | b) & ~(a & b) instead of bitxor(a,b), whenever possible.
• Use // Blah Blah only sparingly (cf. #488).
• Use eye() instead of eye(A) or eye(n,m), whenever possible.
• Use {} instead of cell(), whenever possible.
• Use a+imult(b) instead of complex(a,b), whenever possible.
• Use [f,e]=frexp(x) instead of [f,e]=log2(x), whenever possible.
• Use x instead of x<>0, whenever possible.
• Use x.^(1./n) instead of nthroot(x,n), whenever possible.
• Use a+b*%i instead of complex(a,b) or a+imult(b), whenever possible.
• Use A(:,size(A,2):-1:1) instead of flipdim(A,2), whenever possible.

"Fifty" Ways to Kill Your Scilab 6.x (and Sometimes even Balisc)

1. %t./%f
2. sleep 1
3. eye()\1
4. (1:2):3
5. 1:2:3:4
6. min(1,)
7. a().b=1
8. 1:null()
9. cell(-1)
10. sin{1}=1
11. 1.*.eye()
12. 1./.eye()
13. 1.\.eye()
14. 1./int8(0)
15. 1:insert()
16. x=[];x()=1
17. x=1;x()=[]
18. printf("") or mprintf("") or msprintf("")
19. sparse(1,1)
20. eye()/eye()
21. eye()\eye()
22. expm(eye())
23. p=%s;p{1}=1
24. s="";s{1}=1
25. {list()(:)}
26. speye(-1,-1)
27. if who(),end
28. x(0:1)=1;x=2
29. mprintf("%%")
30. msprintf("%%")
31. min(eye(),"r")
32. max(eye(),"r")
33. spzeros(-2,-1)
34. [null(),null()]
35. ereduc(eye(),1)
36. sprand(-1,1,.1)
37. while who(),end
38. for w=who(),end
39. sparse([0 0],1)
40. read(%io(1),1,1) + [RETURN]
41. cumsum(eye(),"r")
42. sprand(1e3,1e3,1)
43. cumprod(eye(),"r")
44. fromJSON("{""""}")
45. a=struct();a.b=a.b
46. triu([%s+%i,1;1,1])
47. covStart(["a";"b"])
48. [insert(),insert()]
49. write(6,1:3,"(I2)")
50. strsubst("","","","r")
51. s=speye(2,2);s(s==0)=1
52. strsubst('aaa','aa','a')
53. S=struct();S(2,2)=struct()
54. L=list();L(2)=insert();L(1)
55. u=["a","b"];v(1,:)=u,u(:,:)
56. surf(1:2e3,1:2e3,(1:2e3)'*(1:2e3))
57. x=tlist("x");function %x_s(a),end;-x
58. f=gcf();xdel();save(TMPDIR+"/f.sod","f")
59. function f(),ver()(1,2),end;macr2tree(f)
60. a={%s};p=TMPDIR+"/a.sod";save(p,"a");listvarinfile(p)

to be continued ...

Predefined (and Protected) Variables Unique to Balisc

• %balisc

  • Useful to check whether it is Balisc, e.g. use exists("%balisc").
  • Returns a single integer (e.g. 0), which indicates the version of Balisc

Functions Unique to Balisc

• isprotected, protect, unprotect

  • Provide an interface to the protection mechanism of arbitrary variables
  • They supersede predef and are easy to use (cf. #420)

Functions and Keywords Removed in Balisc

• banner useless, nobody needs it
• funptr outdated and useless
• otherwise undocumented and redundant, use otherwise
• resume redundant, use return
• switch undocumented and redundant, use select