Selecting based on criterion on a single column
Clash Royale CLAN TAG#URR8PPP
$begingroup$
I have an array that looks like M = a, b, c, d, where a, b, c, d are column vectors. I want to select rows from this array based on the elements in column c meeting a specified condition.
For example, if I have
M = "cat", 21, 10, 1, "dog", 7, 42, 2, "horse", 30, 1, 19,"hippo", 99, 15,4
I want to take rows from this array based on the condition
c[[i]] >= 10
How could this be done? Ideally I would like to use Select as this can retrieve the sublist.
list-manipulation filtering
edited Feb 6 at 22:29
m_goldberg
86.8k872197
asked Feb 6 at 22:13
MKFMKF
1338
$endgroup$
add a comment |
$begingroup$
I have an array that looks like M = a, b, c, d, where a, b, c, d are column vectors. I want to select rows from this array based on the elements in column c meeting a specified condition.
For example, if I have
M = "cat", 21, 10, 1, "dog", 7, 42, 2, "horse", 30, 1, 19,"hippo", 99, 15,4
I want to take rows from this array based on the condition
c[[i]] >= 10
How could this be done? Ideally I would like to use Select as this can retrieve the sublist.
list-manipulation filtering
edited Feb 6 at 22:29
m_goldberg
86.8k872197
asked Feb 6 at 22:13
MKFMKF
1338
$endgroup$
1
$begingroup$
Essentially a duplicate of Mathematica SE question 45951 "Select record when third column matches certain criterion".
$endgroup$
– Somos
Feb 6 at 22:28
add a comment |
$begingroup$
I have an array that looks like M = a, b, c, d, where a, b, c, d are column vectors. I want to select rows from this array based on the elements in column c meeting a specified condition.
For example, if I have
M = "cat", 21, 10, 1, "dog", 7, 42, 2, "horse", 30, 1, 19,"hippo", 99, 15,4
I want to take rows from this array based on the condition
c[[i]] >= 10
How could this be done? Ideally I would like to use Select as this can retrieve the sublist.
list-manipulation filtering
edited Feb 6 at 22:29
m_goldberg
86.8k872197
asked Feb 6 at 22:13
MKFMKF
1338
$endgroup$
I have an array that looks like M = a, b, c, d, where a, b, c, d are column vectors. I want to select rows from this array based on the elements in column c meeting a specified condition.
For example, if I have
M = "cat", 21, 10, 1, "dog", 7, 42, 2, "horse", 30, 1, 19,"hippo", 99, 15,4
I want to take rows from this array based on the condition
c[[i]] >= 10
How could this be done? Ideally I would like to use Select as this can retrieve the sublist.
list-manipulation filtering
list-manipulation filtering
edited Feb 6 at 22:29
m_goldberg
86.8k872197
asked Feb 6 at 22:13
MKFMKF
1338
edited Feb 6 at 22:29
m_goldberg
86.8k872197
asked Feb 6 at 22:13
MKFMKF
1338
edited Feb 6 at 22:29
m_goldberg
86.8k872197
edited Feb 6 at 22:29
m_goldberg
86.8k872197
edited Feb 6 at 22:29
m_goldberg
86.8k872197
86.8k872197
asked Feb 6 at 22:13
MKFMKF
1338
asked Feb 6 at 22:13
MKFMKF
1338
asked Feb 6 at 22:13
MKFMKF
1338
1338
1
$begingroup$
Essentially a duplicate of Mathematica SE question 45951 "Select record when third column matches certain criterion".
$endgroup$
– Somos
Feb 6 at 22:28
add a comment |
1
$begingroup$
Essentially a duplicate of Mathematica SE question 45951 "Select record when third column matches certain criterion".
$endgroup$
– Somos
Feb 6 at 22:28
1
1
$begingroup$
Essentially a duplicate of Mathematica SE question 45951 "Select record when third column matches certain criterion".
$endgroup$
– Somos
Feb 6 at 22:28
$begingroup$
Essentially a duplicate of Mathematica SE question 45951 "Select record when third column matches certain criterion".
$endgroup$
– Somos
Feb 6 at 22:28
add a comment |
2 Answers
2
active
oldest
votes
$begingroup$
Feels like a duplicate of a bunch of questions, you could probably find by searching this forum... Some basic structures:
Select[M, #[[3]] >= 3 &]
"cat", 21, 10, 1, "dog", 7, 42, 2, "hippo", 99, 15, 4
Cases[M,x_/;x[[3]]>=3]
"cat",21,10,1,"dog",7,42,2,"hippo",99,15,4
answered Feb 6 at 22:25
Vitaliy KaurovVitaliy Kaurov
57.4k6162281
$endgroup$
add a comment |
$begingroup$
Pick[M, UnitStep[M[[All, 3]] - 10], 1]
"cat", 21, 10, 1, "dog", 7, 42, 2, "hippo", 99, 15, 4
More general, you may use
check = # >= 10 &;
Pick[M, check /@ M[[All, 3]]]
answered Feb 6 at 22:20
Henrik SchumacherHenrik Schumacher
55.2k576154
$endgroup$
$begingroup$
Thanks Henrik; this technique wouldn't work if I exchange entries to arbitrary arrays, so is there perhaps a generalisation? I was thinking something likeSelect[M, (#[[All, 3]] >=10) &]- then (if it worked) the type of element wouldn't matter so much i.e. It could generalise to more complicated criteria
$endgroup$
– MKF
Feb 6 at 22:26
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
$begingroup$
Feels like a duplicate of a bunch of questions, you could probably find by searching this forum... Some basic structures:
Select[M, #[[3]] >= 3 &]
"cat", 21, 10, 1, "dog", 7, 42, 2, "hippo", 99, 15, 4
Cases[M,x_/;x[[3]]>=3]
"cat",21,10,1,"dog",7,42,2,"hippo",99,15,4
answered Feb 6 at 22:25
Vitaliy KaurovVitaliy Kaurov
57.4k6162281
$endgroup$
add a comment |
$begingroup$
Feels like a duplicate of a bunch of questions, you could probably find by searching this forum... Some basic structures:
Select[M, #[[3]] >= 3 &]
"cat", 21, 10, 1, "dog", 7, 42, 2, "hippo", 99, 15, 4
Cases[M,x_/;x[[3]]>=3]
"cat",21,10,1,"dog",7,42,2,"hippo",99,15,4
answered Feb 6 at 22:25
Vitaliy KaurovVitaliy Kaurov
57.4k6162281
$endgroup$
add a comment |
$begingroup$
Feels like a duplicate of a bunch of questions, you could probably find by searching this forum... Some basic structures:
Select[M, #[[3]] >= 3 &]
"cat", 21, 10, 1, "dog", 7, 42, 2, "hippo", 99, 15, 4
Cases[M,x_/;x[[3]]>=3]
"cat",21,10,1,"dog",7,42,2,"hippo",99,15,4
answered Feb 6 at 22:25
Vitaliy KaurovVitaliy Kaurov
57.4k6162281
$endgroup$
Feels like a duplicate of a bunch of questions, you could probably find by searching this forum... Some basic structures:
Select[M, #[[3]] >= 3 &]
"cat", 21, 10, 1, "dog", 7, 42, 2, "hippo", 99, 15, 4
Cases[M,x_/;x[[3]]>=3]
"cat",21,10,1,"dog",7,42,2,"hippo",99,15,4
answered Feb 6 at 22:25
Vitaliy KaurovVitaliy Kaurov
57.4k6162281
answered Feb 6 at 22:25
Vitaliy KaurovVitaliy Kaurov
57.4k6162281
answered Feb 6 at 22:25
Vitaliy KaurovVitaliy Kaurov
57.4k6162281
answered Feb 6 at 22:25
Vitaliy KaurovVitaliy Kaurov
57.4k6162281
57.4k6162281
add a comment |
add a comment |
$begingroup$
Pick[M, UnitStep[M[[All, 3]] - 10], 1]
"cat", 21, 10, 1, "dog", 7, 42, 2, "hippo", 99, 15, 4
More general, you may use
check = # >= 10 &;
Pick[M, check /@ M[[All, 3]]]
answered Feb 6 at 22:20
Henrik SchumacherHenrik Schumacher
55.2k576154
$endgroup$
$begingroup$
Thanks Henrik; this technique wouldn't work if I exchange entries to arbitrary arrays, so is there perhaps a generalisation? I was thinking something likeSelect[M, (#[[All, 3]] >=10) &]- then (if it worked) the type of element wouldn't matter so much i.e. It could generalise to more complicated criteria
$endgroup$
– MKF
Feb 6 at 22:26
add a comment |
$begingroup$
Pick[M, UnitStep[M[[All, 3]] - 10], 1]
"cat", 21, 10, 1, "dog", 7, 42, 2, "hippo", 99, 15, 4
More general, you may use
check = # >= 10 &;
Pick[M, check /@ M[[All, 3]]]
answered Feb 6 at 22:20
Henrik SchumacherHenrik Schumacher
55.2k576154
$endgroup$
$begingroup$
Thanks Henrik; this technique wouldn't work if I exchange entries to arbitrary arrays, so is there perhaps a generalisation? I was thinking something likeSelect[M, (#[[All, 3]] >=10) &]- then (if it worked) the type of element wouldn't matter so much i.e. It could generalise to more complicated criteria
$endgroup$
– MKF
Feb 6 at 22:26
add a comment |
$begingroup$
Pick[M, UnitStep[M[[All, 3]] - 10], 1]
"cat", 21, 10, 1, "dog", 7, 42, 2, "hippo", 99, 15, 4
More general, you may use
check = # >= 10 &;
Pick[M, check /@ M[[All, 3]]]
answered Feb 6 at 22:20
Henrik SchumacherHenrik Schumacher
55.2k576154
$endgroup$
Pick[M, UnitStep[M[[All, 3]] - 10], 1]
"cat", 21, 10, 1, "dog", 7, 42, 2, "hippo", 99, 15, 4
More general, you may use
check = # >= 10 &;
Pick[M, check /@ M[[All, 3]]]
answered Feb 6 at 22:20
Henrik SchumacherHenrik Schumacher
55.2k576154
edited Feb 7 at 0:43
answered Feb 6 at 22:20
Henrik SchumacherHenrik Schumacher
55.2k576154
answered Feb 6 at 22:20
Henrik SchumacherHenrik Schumacher
55.2k576154
answered Feb 6 at 22:20
Henrik SchumacherHenrik Schumacher
55.2k576154
55.2k576154
$begingroup$
Thanks Henrik; this technique wouldn't work if I exchange entries to arbitrary arrays, so is there perhaps a generalisation? I was thinking something likeSelect[M, (#[[All, 3]] >=10) &]- then (if it worked) the type of element wouldn't matter so much i.e. It could generalise to more complicated criteria
$endgroup$
– MKF
Feb 6 at 22:26
add a comment |
$begingroup$
Thanks Henrik; this technique wouldn't work if I exchange entries to arbitrary arrays, so is there perhaps a generalisation? I was thinking something likeSelect[M, (#[[All, 3]] >=10) &]- then (if it worked) the type of element wouldn't matter so much i.e. It could generalise to more complicated criteria
$endgroup$
– MKF
Feb 6 at 22:26
$begingroup$
Thanks Henrik; this technique wouldn't work if I exchange entries to arbitrary arrays, so is there perhaps a generalisation? I was thinking something like
Select[M, (#[[All, 3]] >=10) &] - then (if it worked) the type of element wouldn't matter so much i.e. It could generalise to more complicated criteria$endgroup$
– MKF
Feb 6 at 22:26
$begingroup$
Thanks Henrik; this technique wouldn't work if I exchange entries to arbitrary arrays, so is there perhaps a generalisation? I was thinking something like
Select[M, (#[[All, 3]] >=10) &] - then (if it worked) the type of element wouldn't matter so much i.e. It could generalise to more complicated criteria$endgroup$
– MKF
Feb 6 at 22:26
add a comment |
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1
$begingroup$
Essentially a duplicate of Mathematica SE question 45951 "Select record when third column matches certain criterion".
$endgroup$
– Somos
Feb 6 at 22:28