Eliminate empty elements from a list with a specific pattern
$begingroup$
I am really new in this patterns part of Mathematica. Basically what I need to do is eliminate null elements from a list but that has a specific name before the empty element. For example, my list is:
list={"a11-b11-{}", "a12-b11-{1}", "c11-d22-{}", "d33-c22-{2}"}
and I need to obtain
list={"a12-b11-{1}", "d33-c22-{2}"}
The list was created using
list = Flatten[Table[ ToString[namea[[i]] <> "-" <> nameb[[j]] <> "-" <>
ToString[ Select[int[i, j, 0.5], Abs[#] == 0.5 &, 1] ]],
{i, 1, 4}, {j, 1, 4}], 1]
and for some values it writtes {} because there is not a value equal to $0.5$. Until now I have been able to do it term by term as
list//."a11-b11-{}"-> Sequence
but the real list contains a lot of elements and could be almost impossible to do it that way to solve the problem. I think my main problem is that I am not sure how to specify the pattern search (something like " *-name " in gnu/linux). Is there a wise way to do this?. Thanks in advance.
list-manipulation filtering
edited 7 hours ago
Roman
4,66511128
asked 13 hours ago
morsmors
496
$endgroup$
add a comment |
$begingroup$
I am really new in this patterns part of Mathematica. Basically what I need to do is eliminate null elements from a list but that has a specific name before the empty element. For example, my list is:
list={"a11-b11-{}", "a12-b11-{1}", "c11-d22-{}", "d33-c22-{2}"}
and I need to obtain
list={"a12-b11-{1}", "d33-c22-{2}"}
The list was created using
list = Flatten[Table[ ToString[namea[[i]] <> "-" <> nameb[[j]] <> "-" <>
ToString[ Select[int[i, j, 0.5], Abs[#] == 0.5 &, 1] ]],
{i, 1, 4}, {j, 1, 4}], 1]
and for some values it writtes {} because there is not a value equal to $0.5$. Until now I have been able to do it term by term as
list//."a11-b11-{}"-> Sequence
but the real list contains a lot of elements and could be almost impossible to do it that way to solve the problem. I think my main problem is that I am not sure how to specify the pattern search (something like " *-name " in gnu/linux). Is there a wise way to do this?. Thanks in advance.
list-manipulation filtering
edited 7 hours ago
Roman
4,66511128
asked 13 hours ago
morsmors
496
$endgroup$
$begingroup$
Have a look atDeleteCasesandStringMatchQorStringContainsQ.
$endgroup$
– b.gatessucks
12 hours ago
$begingroup$
I think it would be more efficient to first filter out the unwanted cases in theintfunction, and then construct strings only from the remaining ones.
$endgroup$
– Roman
12 hours ago
$begingroup$
@b.gatessucks Thank you, I will look those option in Mathematica.
$endgroup$
– mors
12 hours ago
$begingroup$
@Roman You are right, but I am new ih this cases stuf in Mathematica and I did no know how to do it when I created the list.
$endgroup$
– mors
12 hours ago
add a comment |
$begingroup$
I am really new in this patterns part of Mathematica. Basically what I need to do is eliminate null elements from a list but that has a specific name before the empty element. For example, my list is:
list={"a11-b11-{}", "a12-b11-{1}", "c11-d22-{}", "d33-c22-{2}"}
and I need to obtain
list={"a12-b11-{1}", "d33-c22-{2}"}
The list was created using
list = Flatten[Table[ ToString[namea[[i]] <> "-" <> nameb[[j]] <> "-" <>
ToString[ Select[int[i, j, 0.5], Abs[#] == 0.5 &, 1] ]],
{i, 1, 4}, {j, 1, 4}], 1]
and for some values it writtes {} because there is not a value equal to $0.5$. Until now I have been able to do it term by term as
list//."a11-b11-{}"-> Sequence
but the real list contains a lot of elements and could be almost impossible to do it that way to solve the problem. I think my main problem is that I am not sure how to specify the pattern search (something like " *-name " in gnu/linux). Is there a wise way to do this?. Thanks in advance.
list-manipulation filtering
edited 7 hours ago
Roman
4,66511128
asked 13 hours ago
morsmors
496
$endgroup$
I am really new in this patterns part of Mathematica. Basically what I need to do is eliminate null elements from a list but that has a specific name before the empty element. For example, my list is:
list={"a11-b11-{}", "a12-b11-{1}", "c11-d22-{}", "d33-c22-{2}"}
and I need to obtain
list={"a12-b11-{1}", "d33-c22-{2}"}
The list was created using
list = Flatten[Table[ ToString[namea[[i]] <> "-" <> nameb[[j]] <> "-" <>
ToString[ Select[int[i, j, 0.5], Abs[#] == 0.5 &, 1] ]],
{i, 1, 4}, {j, 1, 4}], 1]
and for some values it writtes {} because there is not a value equal to $0.5$. Until now I have been able to do it term by term as
list//."a11-b11-{}"-> Sequence
but the real list contains a lot of elements and could be almost impossible to do it that way to solve the problem. I think my main problem is that I am not sure how to specify the pattern search (something like " *-name " in gnu/linux). Is there a wise way to do this?. Thanks in advance.
list-manipulation filtering
list-manipulation filtering
edited 7 hours ago
Roman
4,66511128
asked 13 hours ago
morsmors
496
edited 7 hours ago
Roman
4,66511128
asked 13 hours ago
morsmors
496
edited 7 hours ago
Roman
4,66511128
edited 7 hours ago
Roman
4,66511128
edited 7 hours ago
Roman
4,66511128
4,66511128
asked 13 hours ago
morsmors
496
asked 13 hours ago
morsmors
496
asked 13 hours ago
morsmors
496
496
$begingroup$
Have a look atDeleteCasesandStringMatchQorStringContainsQ.
$endgroup$
– b.gatessucks
12 hours ago
$begingroup$
I think it would be more efficient to first filter out the unwanted cases in theintfunction, and then construct strings only from the remaining ones.
$endgroup$
– Roman
12 hours ago
$begingroup$
@b.gatessucks Thank you, I will look those option in Mathematica.
$endgroup$
– mors
12 hours ago
$begingroup$
@Roman You are right, but I am new ih this cases stuf in Mathematica and I did no know how to do it when I created the list.
$endgroup$
– mors
12 hours ago
add a comment |
$begingroup$
Have a look atDeleteCasesandStringMatchQorStringContainsQ.
$endgroup$
– b.gatessucks
12 hours ago
$begingroup$
I think it would be more efficient to first filter out the unwanted cases in theintfunction, and then construct strings only from the remaining ones.
$endgroup$
– Roman
12 hours ago
$begingroup$
@b.gatessucks Thank you, I will look those option in Mathematica.
$endgroup$
– mors
12 hours ago
$begingroup$
@Roman You are right, but I am new ih this cases stuf in Mathematica and I did no know how to do it when I created the list.
$endgroup$
– mors
12 hours ago
$begingroup$
Have a look at
DeleteCases and StringMatchQ or StringContainsQ.$endgroup$
– b.gatessucks
12 hours ago
$begingroup$
Have a look at
DeleteCases and StringMatchQ or StringContainsQ.$endgroup$
– b.gatessucks
12 hours ago
$begingroup$
I think it would be more efficient to first filter out the unwanted cases in the
int function, and then construct strings only from the remaining ones.$endgroup$
– Roman
12 hours ago
$begingroup$
I think it would be more efficient to first filter out the unwanted cases in the
int function, and then construct strings only from the remaining ones.$endgroup$
– Roman
12 hours ago
$begingroup$
@b.gatessucks Thank you, I will look those option in Mathematica.
$endgroup$
– mors
12 hours ago
$begingroup$
@b.gatessucks Thank you, I will look those option in Mathematica.
$endgroup$
– mors
12 hours ago
$begingroup$
@Roman You are right, but I am new ih this cases stuf in Mathematica and I did no know how to do it when I created the list.
$endgroup$
– mors
12 hours ago
$begingroup$
@Roman You are right, but I am new ih this cases stuf in Mathematica and I did no know how to do it when I created the list.
$endgroup$
– mors
12 hours ago
add a comment |
2 Answers
2
active
oldest
votes
$begingroup$
If the list elements are strings, as it appears after your comment, you can use Select with a string pattern:
list = {"a11-b11-{}", "a12-b11-{1}", "c11-d22-{}", "d33-c22-{2}"};
Select[list, Not@*StringMatchQ[__ ~~ "{}"]]
{"a12-b11-{1}", "d33-c22-{2}"}
You could also Select before making the strings:
L = DeleteCases[
Flatten[
Table[
{namea[[i]], nameb[[j]], Select[int[i, j, 0.5], Abs[#] == 0.5 &, 1]},
{i, 4}, {j, 4}],
1],
{_, _, {}}];
and then make these into strings:
StringRiffle[ToString /@ #, "-"] & /@ L
I can't check this because you didn't supply functioning code.
answered 12 hours ago
RomanRoman
4,66511128
$endgroup$
$begingroup$
Thank you, I forgot to specify the way the list is created. I create the list as 'list = Flatten[Table[ ToString[namea[[i]] <> "-" <> nameb[[j]] <> "-" <> ToString[ Select[int[i, j, 0.5], Abs[#] == 0.5 &, 1] ]], {i, 1, 4}, {j, 1, 4}], 1] '
$endgroup$
– mors
12 hours ago
add a comment |
$begingroup$
In 10.1, two functions were added to handle a pair of very common cases: StringStartsQ and StringEndsQ which return True if the string matches a pattern at the beginning or end, respectively. So, while Roman's answer gives you the full general form, most of the pattern can be eliminated by using
list = {"a11-b11-{}", "a12-b11-{1}", "c11-d22-{}", "d33-c22-{2}"};
Select[list, Not@*StringEndsQ["{}"]]
instead.
answered 6 hours ago
rcollyerrcollyer
28.6k674166
$endgroup$
add a comment |
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2 Answers
2
active
oldest
votes
2 Answers
2
active
oldest
votes
active
oldest
votes
active
oldest
votes
$begingroup$
If the list elements are strings, as it appears after your comment, you can use Select with a string pattern:
list = {"a11-b11-{}", "a12-b11-{1}", "c11-d22-{}", "d33-c22-{2}"};
Select[list, Not@*StringMatchQ[__ ~~ "{}"]]
{"a12-b11-{1}", "d33-c22-{2}"}
You could also Select before making the strings:
L = DeleteCases[
Flatten[
Table[
{namea[[i]], nameb[[j]], Select[int[i, j, 0.5], Abs[#] == 0.5 &, 1]},
{i, 4}, {j, 4}],
1],
{_, _, {}}];
and then make these into strings:
StringRiffle[ToString /@ #, "-"] & /@ L
I can't check this because you didn't supply functioning code.
answered 12 hours ago
RomanRoman
4,66511128
$endgroup$
$begingroup$
Thank you, I forgot to specify the way the list is created. I create the list as 'list = Flatten[Table[ ToString[namea[[i]] <> "-" <> nameb[[j]] <> "-" <> ToString[ Select[int[i, j, 0.5], Abs[#] == 0.5 &, 1] ]], {i, 1, 4}, {j, 1, 4}], 1] '
$endgroup$
– mors
12 hours ago
add a comment |
$begingroup$
If the list elements are strings, as it appears after your comment, you can use Select with a string pattern:
list = {"a11-b11-{}", "a12-b11-{1}", "c11-d22-{}", "d33-c22-{2}"};
Select[list, Not@*StringMatchQ[__ ~~ "{}"]]
{"a12-b11-{1}", "d33-c22-{2}"}
You could also Select before making the strings:
L = DeleteCases[
Flatten[
Table[
{namea[[i]], nameb[[j]], Select[int[i, j, 0.5], Abs[#] == 0.5 &, 1]},
{i, 4}, {j, 4}],
1],
{_, _, {}}];
and then make these into strings:
StringRiffle[ToString /@ #, "-"] & /@ L
I can't check this because you didn't supply functioning code.
answered 12 hours ago
RomanRoman
4,66511128
$endgroup$
$begingroup$
Thank you, I forgot to specify the way the list is created. I create the list as 'list = Flatten[Table[ ToString[namea[[i]] <> "-" <> nameb[[j]] <> "-" <> ToString[ Select[int[i, j, 0.5], Abs[#] == 0.5 &, 1] ]], {i, 1, 4}, {j, 1, 4}], 1] '
$endgroup$
– mors
12 hours ago
add a comment |
$begingroup$
If the list elements are strings, as it appears after your comment, you can use Select with a string pattern:
list = {"a11-b11-{}", "a12-b11-{1}", "c11-d22-{}", "d33-c22-{2}"};
Select[list, Not@*StringMatchQ[__ ~~ "{}"]]
{"a12-b11-{1}", "d33-c22-{2}"}
You could also Select before making the strings:
L = DeleteCases[
Flatten[
Table[
{namea[[i]], nameb[[j]], Select[int[i, j, 0.5], Abs[#] == 0.5 &, 1]},
{i, 4}, {j, 4}],
1],
{_, _, {}}];
and then make these into strings:
StringRiffle[ToString /@ #, "-"] & /@ L
I can't check this because you didn't supply functioning code.
answered 12 hours ago
RomanRoman
4,66511128
$endgroup$
If the list elements are strings, as it appears after your comment, you can use Select with a string pattern:
list = {"a11-b11-{}", "a12-b11-{1}", "c11-d22-{}", "d33-c22-{2}"};
Select[list, Not@*StringMatchQ[__ ~~ "{}"]]
{"a12-b11-{1}", "d33-c22-{2}"}
You could also Select before making the strings:
L = DeleteCases[
Flatten[
Table[
{namea[[i]], nameb[[j]], Select[int[i, j, 0.5], Abs[#] == 0.5 &, 1]},
{i, 4}, {j, 4}],
1],
{_, _, {}}];
and then make these into strings:
StringRiffle[ToString /@ #, "-"] & /@ L
I can't check this because you didn't supply functioning code.
answered 12 hours ago
RomanRoman
4,66511128
edited 8 hours ago
answered 12 hours ago
RomanRoman
4,66511128
answered 12 hours ago
RomanRoman
4,66511128
answered 12 hours ago
RomanRoman
4,66511128
4,66511128
$begingroup$
Thank you, I forgot to specify the way the list is created. I create the list as 'list = Flatten[Table[ ToString[namea[[i]] <> "-" <> nameb[[j]] <> "-" <> ToString[ Select[int[i, j, 0.5], Abs[#] == 0.5 &, 1] ]], {i, 1, 4}, {j, 1, 4}], 1] '
$endgroup$
– mors
12 hours ago
add a comment |
$begingroup$
Thank you, I forgot to specify the way the list is created. I create the list as 'list = Flatten[Table[ ToString[namea[[i]] <> "-" <> nameb[[j]] <> "-" <> ToString[ Select[int[i, j, 0.5], Abs[#] == 0.5 &, 1] ]], {i, 1, 4}, {j, 1, 4}], 1] '
$endgroup$
– mors
12 hours ago
$begingroup$
Thank you, I forgot to specify the way the list is created. I create the list as 'list = Flatten[Table[ ToString[namea[[i]] <> "-" <> nameb[[j]] <> "-" <> ToString[ Select[int[i, j, 0.5], Abs[#] == 0.5 &, 1] ]], {i, 1, 4}, {j, 1, 4}], 1] '
$endgroup$
– mors
12 hours ago
$begingroup$
Thank you, I forgot to specify the way the list is created. I create the list as 'list = Flatten[Table[ ToString[namea[[i]] <> "-" <> nameb[[j]] <> "-" <> ToString[ Select[int[i, j, 0.5], Abs[#] == 0.5 &, 1] ]], {i, 1, 4}, {j, 1, 4}], 1] '
$endgroup$
– mors
12 hours ago
add a comment |
$begingroup$
In 10.1, two functions were added to handle a pair of very common cases: StringStartsQ and StringEndsQ which return True if the string matches a pattern at the beginning or end, respectively. So, while Roman's answer gives you the full general form, most of the pattern can be eliminated by using
list = {"a11-b11-{}", "a12-b11-{1}", "c11-d22-{}", "d33-c22-{2}"};
Select[list, Not@*StringEndsQ["{}"]]
instead.
answered 6 hours ago
rcollyerrcollyer
28.6k674166
$endgroup$
add a comment |
$begingroup$
In 10.1, two functions were added to handle a pair of very common cases: StringStartsQ and StringEndsQ which return True if the string matches a pattern at the beginning or end, respectively. So, while Roman's answer gives you the full general form, most of the pattern can be eliminated by using
list = {"a11-b11-{}", "a12-b11-{1}", "c11-d22-{}", "d33-c22-{2}"};
Select[list, Not@*StringEndsQ["{}"]]
instead.
answered 6 hours ago
rcollyerrcollyer
28.6k674166
$endgroup$
add a comment |
$begingroup$
In 10.1, two functions were added to handle a pair of very common cases: StringStartsQ and StringEndsQ which return True if the string matches a pattern at the beginning or end, respectively. So, while Roman's answer gives you the full general form, most of the pattern can be eliminated by using
list = {"a11-b11-{}", "a12-b11-{1}", "c11-d22-{}", "d33-c22-{2}"};
Select[list, Not@*StringEndsQ["{}"]]
instead.
answered 6 hours ago
rcollyerrcollyer
28.6k674166
$endgroup$
In 10.1, two functions were added to handle a pair of very common cases: StringStartsQ and StringEndsQ which return True if the string matches a pattern at the beginning or end, respectively. So, while Roman's answer gives you the full general form, most of the pattern can be eliminated by using
list = {"a11-b11-{}", "a12-b11-{1}", "c11-d22-{}", "d33-c22-{2}"};
Select[list, Not@*StringEndsQ["{}"]]
instead.
answered 6 hours ago
rcollyerrcollyer
28.6k674166
answered 6 hours ago
rcollyerrcollyer
28.6k674166
answered 6 hours ago
rcollyerrcollyer
28.6k674166
answered 6 hours ago
rcollyerrcollyer
28.6k674166
28.6k674166
add a comment |
add a comment |
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$begingroup$
Have a look at
DeleteCasesandStringMatchQorStringContainsQ.$endgroup$
– b.gatessucks
12 hours ago
$begingroup$
I think it would be more efficient to first filter out the unwanted cases in the
intfunction, and then construct strings only from the remaining ones.$endgroup$
– Roman
12 hours ago
$begingroup$
@b.gatessucks Thank you, I will look those option in Mathematica.
$endgroup$
– mors
12 hours ago
$begingroup$
@Roman You are right, but I am new ih this cases stuf in Mathematica and I did no know how to do it when I created the list.
$endgroup$
– mors
12 hours ago