Eliminate empty elements from a list with a specific pattern The 2019 Stack Overflow Developer Survey Results Are In Announcing the arrival of Valued Associate #679: Cesar Manara Planned maintenance scheduled April 17/18, 2019 at 00:00UTC (8:00pm US/Eastern)List operation on specific elementsSelect elements from list with given headSelecting elements from a list with nullsReplace empty list elements with patternReplacing Non-Constant Elements from List with Patternselecting elements from a list with two numbersRemoving elements of a specific length from a listEliminate types of elements from the listListPlot3D with empty matrix elementsDelete a large pattern from one list
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Eliminate empty elements from a list with a specific pattern
The 2019 Stack Overflow Developer Survey Results Are In
Announcing the arrival of Valued Associate #679: Cesar Manara
Planned maintenance scheduled April 17/18, 2019 at 00:00UTC (8:00pm US/Eastern)List operation on specific elementsSelect elements from list with given headSelecting elements from a list with nullsReplace empty list elements with patternReplacing Non-Constant Elements from List with Patternselecting elements from a list with two numbersRemoving elements of a specific length from a listEliminate types of elements from the listListPlot3D with empty matrix elementsDelete a large pattern from one list
$begingroup$
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
$endgroup$
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
$endgroup$
$begingroup$
Have a look atDeleteCases
andStringMatchQ
orStringContainsQ
.
$endgroup$
– b.gatessucks
Apr 8 at 14:31
$begingroup$
I think it would be more efficient to first filter out the unwanted cases in theint
function, and then construct strings only from the remaining ones.
$endgroup$
– Roman
Apr 8 at 15:01
$begingroup$
@b.gatessucks Thank you, I will look those option in Mathematica.
$endgroup$
– mors
Apr 8 at 15:07
$begingroup$
@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
Apr 8 at 15:09
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
$endgroup$
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 Apr 8 at 19:43
Roman
5,20011131
5,20011131
asked Apr 8 at 14:13
morsmors
716
716
$begingroup$
Have a look atDeleteCases
andStringMatchQ
orStringContainsQ
.
$endgroup$
– b.gatessucks
Apr 8 at 14:31
$begingroup$
I think it would be more efficient to first filter out the unwanted cases in theint
function, and then construct strings only from the remaining ones.
$endgroup$
– Roman
Apr 8 at 15:01
$begingroup$
@b.gatessucks Thank you, I will look those option in Mathematica.
$endgroup$
– mors
Apr 8 at 15:07
$begingroup$
@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
Apr 8 at 15:09
add a comment |
$begingroup$
Have a look atDeleteCases
andStringMatchQ
orStringContainsQ
.
$endgroup$
– b.gatessucks
Apr 8 at 14:31
$begingroup$
I think it would be more efficient to first filter out the unwanted cases in theint
function, and then construct strings only from the remaining ones.
$endgroup$
– Roman
Apr 8 at 15:01
$begingroup$
@b.gatessucks Thank you, I will look those option in Mathematica.
$endgroup$
– mors
Apr 8 at 15:07
$begingroup$
@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
Apr 8 at 15:09
$begingroup$
Have a look at
DeleteCases
and StringMatchQ
or StringContainsQ
.$endgroup$
– b.gatessucks
Apr 8 at 14:31
$begingroup$
Have a look at
DeleteCases
and StringMatchQ
or StringContainsQ
.$endgroup$
– b.gatessucks
Apr 8 at 14:31
$begingroup$
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
Apr 8 at 15:01
$begingroup$
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
Apr 8 at 15:01
$begingroup$
@b.gatessucks Thank you, I will look those option in Mathematica.
$endgroup$
– mors
Apr 8 at 15:07
$begingroup$
@b.gatessucks Thank you, I will look those option in Mathematica.
$endgroup$
– mors
Apr 8 at 15:07
$begingroup$
@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
Apr 8 at 15:09
$begingroup$
@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
Apr 8 at 15:09
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.
$endgroup$
$begingroup$
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
Apr 8 at 14:39
$begingroup$
Thank you. The second part of your answer was really helpfull.
$endgroup$
– mors
yesterday
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.
$endgroup$
$begingroup$
Than you, it looks really useful, I will try to implement it.
$endgroup$
– mors
yesterday
add a comment |
Your Answer
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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.
$endgroup$
$begingroup$
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
Apr 8 at 14:39
$begingroup$
Thank you. The second part of your answer was really helpfull.
$endgroup$
– mors
yesterday
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.
$endgroup$
$begingroup$
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
Apr 8 at 14:39
$begingroup$
Thank you. The second part of your answer was really helpfull.
$endgroup$
– mors
yesterday
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.
$endgroup$
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.
edited Apr 8 at 18:44
answered Apr 8 at 14:37
RomanRoman
5,20011131
5,20011131
$begingroup$
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
Apr 8 at 14:39
$begingroup$
Thank you. The second part of your answer was really helpfull.
$endgroup$
– mors
yesterday
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
Apr 8 at 14:39
$begingroup$
Thank you. The second part of your answer was really helpfull.
$endgroup$
– mors
yesterday
$begingroup$
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
Apr 8 at 14:39
$begingroup$
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
Apr 8 at 14:39
$begingroup$
Thank you. The second part of your answer was really helpfull.
$endgroup$
– mors
yesterday
$begingroup$
Thank you. The second part of your answer was really helpfull.
$endgroup$
– mors
yesterday
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.
$endgroup$
$begingroup$
Than you, it looks really useful, I will try to implement it.
$endgroup$
– mors
yesterday
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.
$endgroup$
$begingroup$
Than you, it looks really useful, I will try to implement it.
$endgroup$
– mors
yesterday
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.
$endgroup$
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 Apr 8 at 20:44
rcollyerrcollyer
28.7k674166
28.7k674166
$begingroup$
Than you, it looks really useful, I will try to implement it.
$endgroup$
– mors
yesterday
add a comment |
$begingroup$
Than you, it looks really useful, I will try to implement it.
$endgroup$
– mors
yesterday
$begingroup$
Than you, it looks really useful, I will try to implement it.
$endgroup$
– mors
yesterday
$begingroup$
Than you, it looks really useful, I will try to implement it.
$endgroup$
– mors
yesterday
add a comment |
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$begingroup$
Have a look at
DeleteCases
andStringMatchQ
orStringContainsQ
.$endgroup$
– b.gatessucks
Apr 8 at 14:31
$begingroup$
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
Apr 8 at 15:01
$begingroup$
@b.gatessucks Thank you, I will look those option in Mathematica.
$endgroup$
– mors
Apr 8 at 15:07
$begingroup$
@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
Apr 8 at 15:09