& and |

Dear useRs,

I feel really stupid, but I cannot understand why "&" doesn't work as I
expect, while "|" does.

I have the following vector:
mydata <- c("SSFA-ConfoMap_GuineaPigs_NMPfilled.csv",
"SSFA-ConfoMap_Lithics_NMPfilled.csv",
"SSFA-ConfoMap_Sheeps_NMPfilled.csv", "SSFA-Toothfrax_GuineaPigs.xlsx",
"SSFA-Toothfrax_Lithics.xlsx", "SSFA-Toothfrax_Sheeps.xlsx")
and I want to find the values that include both "ConfoMap" and
"GuineaPigs".

If I do:
grep("ConfoMap&GuineaPigs", mydata, value=TRUE)
it returns an empty vector, character(0).

But if I do:
grep("ConfoMap|GuineaPigs", mydata, value=TRUE)
it returns all the elements that include either "ConfoMap" or
"GuineaPigs", as I would expect.

So what is wrong with my "&" construct? How can I return the elements
that include both parts?

Thank you for your help!
Ivan

--
Dr. Ivan Calandra
TraCEr, laboratory for Traceology and Controlled Experiments
MONREPOS Archaeological Research Centre and
Museum for Human Behavioural Evolution
Schloss Monrepos
56567 Neuwied, Germany
+49 (0) 2631 9772-243
https://www.researchgate.net/profile/Ivan_Calandra

"&" is not a regex metacharacter.
See ?regexp

Bert Gunter

"The trouble with having an open mind is that people keep coming along and
sticking things into it."
-- Opus (aka Berkeley Breathed in his "Bloom County" comic strip )


On Wed, Aug 19, 2020 at 7:53 AM Ivan Calandra <calandra at rgzm.de> wrote:

Dear useRs,

I feel really stupid, but I cannot understand why "&" doesn't work as I
expect, while "|" does.

I have the following vector:
mydata <- c("SSFA-ConfoMap_GuineaPigs_NMPfilled.csv",
"SSFA-ConfoMap_Lithics_NMPfilled.csv",
"SSFA-ConfoMap_Sheeps_NMPfilled.csv", "SSFA-Toothfrax_GuineaPigs.xlsx",
"SSFA-Toothfrax_Lithics.xlsx", "SSFA-Toothfrax_Sheeps.xlsx")
and I want to find the values that include both "ConfoMap" and
"GuineaPigs".

If I do:
grep("ConfoMap&GuineaPigs", mydata, value=TRUE)
it returns an empty vector, character(0).

But if I do:
grep("ConfoMap|GuineaPigs", mydata, value=TRUE)
it returns all the elements that include either "ConfoMap" or
"GuineaPigs", as I would expect.

So what is wrong with my "&" construct? How can I return the elements
that include both parts?

Thank you for your help!
Ivan

--
Dr. Ivan Calandra
TraCEr, laboratory for Traceology and Controlled Experiments
MONREPOS Archaeological Research Centre and
Museum for Human Behavioural Evolution
Schloss Monrepos
56567 Neuwied, Germany
+49 (0) 2631 9772-243
https://www.researchgate.net/profile/Ivan_Calandra

        [[alternative HTML version deleted]]

"&" is not a regex metacharacter.
See ?regexp

Bert Gunter

"The trouble with having an open mind is that people keep coming along
and sticking things into it."
-- Opus (aka Berkeley Breathed in his "Bloom County" comic strip )


On Wed, Aug 19, 2020 at 7:53 AM Ivan Calandra <calandra at rgzm.de
<mailto:calandra at rgzm.de>> wrote:

    Dear useRs,

    I feel really stupid, but I cannot understand why "&" doesn't work
    as I
    expect, while "|" does.

    I have the following vector:
    mydata <- c("SSFA-ConfoMap_GuineaPigs_NMPfilled.csv",
    "SSFA-ConfoMap_Lithics_NMPfilled.csv",?
    "SSFA-ConfoMap_Sheeps_NMPfilled.csv",
    "SSFA-Toothfrax_GuineaPigs.xlsx",
    "SSFA-Toothfrax_Lithics.xlsx", "SSFA-Toothfrax_Sheeps.xlsx")
    and I want to find the values that include both "ConfoMap" and
    "GuineaPigs".

    If I do:
    grep("ConfoMap&GuineaPigs", mydata, value=TRUE)
    it returns an empty vector, character(0).

    But if I do:
    grep("ConfoMap|GuineaPigs", mydata, value=TRUE)
    it returns all the elements that include either "ConfoMap" or
    "GuineaPigs", as I would expect.

    So what is wrong with my "&" construct? How can I return the elements
    that include both parts?

    Thank you for your help!
    Ivan

    -- 
    Dr. Ivan Calandra
    TraCEr, laboratory for Traceology and Controlled Experiments
    MONREPOS Archaeological Research Centre and
    Museum for Human Behavioural Evolution
    Schloss Monrepos
    56567 Neuwied, Germany
    +49 (0) 2631 9772-243
    https://www.researchgate.net/profile/Ivan_Calandra

mydata[ intersect( grep("ConfoMap", mydata), grep("GuineaPigs",
mydata) ?) ]



On Wed, Aug 19, 2020 at 6:13 PM Bert Gunter <bgunter.4567 at gmail.com
<mailto:bgunter.4567 at gmail.com>> wrote:

    "&" is not a regex metacharacter.
    See ?regexp

    Bert Gunter

    "The trouble with having an open mind is that people keep coming
    along and
    sticking things into it."
    -- Opus (aka Berkeley Breathed in his "Bloom County" comic strip )


    On Wed, Aug 19, 2020 at 7:53 AM Ivan Calandra <calandra at rgzm.de
    <mailto:calandra at rgzm.de>> wrote:

    > Dear useRs,
    >
    > I feel really stupid, but I cannot understand why "&" doesn't

    work as I

    > expect, while "|" does.
    >
    > I have the following vector:
    > mydata <- c("SSFA-ConfoMap_GuineaPigs_NMPfilled.csv",
    > "SSFA-ConfoMap_Lithics_NMPfilled.csv",
    > "SSFA-ConfoMap_Sheeps_NMPfilled.csv",

    "SSFA-Toothfrax_GuineaPigs.xlsx",

    > "SSFA-Toothfrax_Lithics.xlsx", "SSFA-Toothfrax_Sheeps.xlsx")
    > and I want to find the values that include both "ConfoMap" and
    > "GuineaPigs".
    >
    > If I do:
    > grep("ConfoMap&GuineaPigs", mydata, value=TRUE)
    > it returns an empty vector, character(0).
    >
    > But if I do:
    > grep("ConfoMap|GuineaPigs", mydata, value=TRUE)
    > it returns all the elements that include either "ConfoMap" or
    > "GuineaPigs", as I would expect.
    >
    > So what is wrong with my "&" construct? How can I return the

    elements

    > that include both parts?
    >
    > Thank you for your help!
    > Ivan
    >
    > --
    > Dr. Ivan Calandra
    > TraCEr, laboratory for Traceology and Controlled Experiments
    > MONREPOS Archaeological Research Centre and
    > Museum for Human Behavioural Evolution
    > Schloss Monrepos
    > 56567 Neuwied, Germany
    > +49 (0) 2631 9772-243
    > https://www.researchgate.net/profile/Ivan_Calandra
    >
    > ______________________________________________
    > R-help at r-project.org <mailto:R-help at r-project.org> mailing list

    -- To UNSUBSCRIBE and more, see

    > https://stat.ethz.ch/mailman/listinfo/r-help
    > PLEASE do read the posting guide
    > http://www.R-project.org/posting-guide.html

    ? ? ? ? [[alternative HTML version deleted]]

Thank you Bert for the pointer.

So I guess the solution is:
grep("ConfoMap.+GuineaPigs", mydata, value=TRUE)

This is not the case here, but what if "GuineaPigs" comes before
"ConfoMap"?
Of course I could do two "grep()" calls, but if there a better solution?

Ivan

--
Dr. Ivan Calandra
TraCEr, laboratory for Traceology and Controlled Experiments
MONREPOS Archaeological Research Centre and
Museum for Human Behavioural Evolution
Schloss Monrepos
56567 Neuwied, Germany
+49 (0) 2631 9772-243
https://www.researchgate.net/profile/Ivan_Calandra

On 19/08/2020 17:07, Bert Gunter wrote:

"&" is not a regex metacharacter.
See ?regexp

Bert Gunter

"The trouble with having an open mind is that people keep coming along
and sticking things into it."
-- Opus (aka Berkeley Breathed in his "Bloom County" comic strip )


On Wed, Aug 19, 2020 at 7:53 AM Ivan Calandra <calandra at rgzm.de
<mailto:calandra at rgzm.de>> wrote:

    Dear useRs,

    I feel really stupid, but I cannot understand why "&" doesn't work
    as I
    expect, while "|" does.

    I have the following vector:
    mydata <- c("SSFA-ConfoMap_GuineaPigs_NMPfilled.csv",
    "SSFA-ConfoMap_Lithics_NMPfilled.csv",
    "SSFA-ConfoMap_Sheeps_NMPfilled.csv",
    "SSFA-Toothfrax_GuineaPigs.xlsx",
    "SSFA-Toothfrax_Lithics.xlsx", "SSFA-Toothfrax_Sheeps.xlsx")
    and I want to find the values that include both "ConfoMap" and
    "GuineaPigs".

    If I do:
    grep("ConfoMap&GuineaPigs", mydata, value=TRUE)
    it returns an empty vector, character(0).

    But if I do:
    grep("ConfoMap|GuineaPigs", mydata, value=TRUE)
    it returns all the elements that include either "ConfoMap" or
    "GuineaPigs", as I would expect.

    So what is wrong with my "&" construct? How can I return the elements
    that include both parts?

    Thank you for your help!
    Ivan

    --
    Dr. Ivan Calandra
    TraCEr, laboratory for Traceology and Controlled Experiments
    MONREPOS Archaeological Research Centre and
    Museum for Human Behavioural Evolution
    Schloss Monrepos
    56567 Neuwied, Germany
    +49 (0) 2631 9772-243
    https://www.researchgate.net/profile/Ivan_Calandra

Well... wouldn't it be:

rep("(ConfoMap.*GuineaPigs)|(GuineaPigs.*ConfoMap)", mydata, value=TRUE)

Bert Gunter

"The trouble with having an open mind is that people keep coming along
and sticking things into it."
-- Opus (aka Berkeley Breathed in his "Bloom County" comic strip )


On Wed, Aug 19, 2020 at 8:23 AM Ivan Calandra <calandra at rgzm.de
<mailto:calandra at rgzm.de>> wrote:

    Thank you Bert for the pointer.

    So I guess the solution is:
    grep("ConfoMap.+GuineaPigs", mydata, value=TRUE)

    This is not the case here, but what if "GuineaPigs" comes before
    "ConfoMap"?
    Of course I could do two "grep()" calls, but if there a better
    solution?

    Ivan

    --
    Dr. Ivan Calandra
    TraCEr, laboratory for Traceology and Controlled Experiments
    MONREPOS Archaeological Research Centre and
    Museum for Human Behavioural Evolution
    Schloss Monrepos
    56567 Neuwied, Germany
    +49 (0) 2631 9772-243
    https://www.researchgate.net/profile/Ivan_Calandra

    On 19/08/2020 17:07, Bert Gunter wrote:

    > "&" is not a regex metacharacter.
    > See ?regexp
    >
    > Bert Gunter
    >
    > "The trouble with having an open mind is that people keep coming

    along

    > and sticking things into it."
    > -- Opus (aka Berkeley Breathed in his "Bloom County" comic strip )
    >
    >
    > On Wed, Aug 19, 2020 at 7:53 AM Ivan Calandra <calandra at rgzm.de

    <mailto:calandra at rgzm.de>

    > <mailto:calandra at rgzm.de <mailto:calandra at rgzm.de>>> wrote:
    >
    >? ? ?Dear useRs,
    >
    >? ? ?I feel really stupid, but I cannot understand why "&"

    doesn't work

    >? ? ?as I
    >? ? ?expect, while "|" does.
    >
    >? ? ?I have the following vector:
    >? ? ?mydata <- c("SSFA-ConfoMap_GuineaPigs_NMPfilled.csv",
    >? ? ?"SSFA-ConfoMap_Lithics_NMPfilled.csv",?
    >? ? ?"SSFA-ConfoMap_Sheeps_NMPfilled.csv",
    >? ? ?"SSFA-Toothfrax_GuineaPigs.xlsx",
    >? ? ?"SSFA-Toothfrax_Lithics.xlsx", "SSFA-Toothfrax_Sheeps.xlsx")
    >? ? ?and I want to find the values that include both "ConfoMap" and
    >? ? ?"GuineaPigs".
    >
    >? ? ?If I do:
    >? ? ?grep("ConfoMap&GuineaPigs", mydata, value=TRUE)
    >? ? ?it returns an empty vector, character(0).
    >
    >? ? ?But if I do:
    >? ? ?grep("ConfoMap|GuineaPigs", mydata, value=TRUE)
    >? ? ?it returns all the elements that include either "ConfoMap" or
    >? ? ?"GuineaPigs", as I would expect.
    >
    >? ? ?So what is wrong with my "&" construct? How can I return the

    elements

    >? ? ?that include both parts?
    >
    >? ? ?Thank you for your help!
    >? ? ?Ivan
    >
    >? ? ?--
    >? ? ?Dr. Ivan Calandra
    >? ? ?TraCEr, laboratory for Traceology and Controlled Experiments
    >? ? ?MONREPOS Archaeological Research Centre and
    >? ? ?Museum for Human Behavioural Evolution
    >? ? ?Schloss Monrepos
    >? ? ?56567 Neuwied, Germany
    >? ? ?+49 (0) 2631 9772-243
    >? ? ?https://www.researchgate.net/profile/Ivan_Calandra
    >
    >? ? ?______________________________________________
    >? ? ?R-help at r-project.org <mailto:R-help at r-project.org>

    <mailto:R-help at r-project.org <mailto:R-help at r-project.org>>
    mailing list --

    >? ? ?To UNSUBSCRIBE and more, see
    >? ? ?https://stat.ethz.ch/mailman/listinfo/r-help
    >? ? ?PLEASE do read the posting guide
    >? ? ?http://www.R-project.org/posting-guide.html

    code.

    >

Thank you Eric, I didn't think about intersect().

Now I'm trying to do that in tidyverse with pipes, and I think that's
too much for me for now!

Ivan

--
Dr. Ivan Calandra
TraCEr, laboratory for Traceology and Controlled Experiments
MONREPOS Archaeological Research Centre and
Museum for Human Behavioural Evolution
Schloss Monrepos
56567 Neuwied, Germany
+49 (0) 2631 9772-243
https://www.researchgate.net/profile/Ivan_Calandra

On 19/08/2020 17:17, Eric Berger wrote:

mydata[ intersect( grep("ConfoMap", mydata), grep("GuineaPigs",
mydata)  ) ]



On Wed, Aug 19, 2020 at 6:13 PM Bert Gunter <bgunter.4567 at gmail.com
<mailto:bgunter.4567 at gmail.com>> wrote:

    "&" is not a regex metacharacter.
    See ?regexp

    Bert Gunter

    "The trouble with having an open mind is that people keep coming
    along and
    sticking things into it."
    -- Opus (aka Berkeley Breathed in his "Bloom County" comic strip )


    On Wed, Aug 19, 2020 at 7:53 AM Ivan Calandra <calandra at rgzm.de
    <mailto:calandra at rgzm.de>> wrote:

    > Dear useRs,
    >
    > I feel really stupid, but I cannot understand why "&" doesn't

    work as I

    > expect, while "|" does.
    >
    > I have the following vector:
    > mydata <- c("SSFA-ConfoMap_GuineaPigs_NMPfilled.csv",
    > "SSFA-ConfoMap_Lithics_NMPfilled.csv",
    > "SSFA-ConfoMap_Sheeps_NMPfilled.csv",

    "SSFA-Toothfrax_GuineaPigs.xlsx",

    > "SSFA-Toothfrax_Lithics.xlsx", "SSFA-Toothfrax_Sheeps.xlsx")
    > and I want to find the values that include both "ConfoMap" and
    > "GuineaPigs".
    >
    > If I do:
    > grep("ConfoMap&GuineaPigs", mydata, value=TRUE)
    > it returns an empty vector, character(0).
    >
    > But if I do:
    > grep("ConfoMap|GuineaPigs", mydata, value=TRUE)
    > it returns all the elements that include either "ConfoMap" or
    > "GuineaPigs", as I would expect.
    >
    > So what is wrong with my "&" construct? How can I return the

    elements

    > that include both parts?
    >
    > Thank you for your help!
    > Ivan
    >
    > --
    > Dr. Ivan Calandra
    > TraCEr, laboratory for Traceology and Controlled Experiments
    > MONREPOS Archaeological Research Centre and
    > Museum for Human Behavioural Evolution
    > Schloss Monrepos
    > 56567 Neuwied, Germany
    > +49 (0) 2631 9772-243
    > https://www.researchgate.net/profile/Ivan_Calandra
    >
    > ______________________________________________
    > R-help at r-project.org <mailto:R-help at r-project.org> mailing list

    -- To UNSUBSCRIBE and more, see

    > https://stat.ethz.ch/mailman/listinfo/r-help
    > PLEASE do read the posting guide
    > http://www.R-project.org/posting-guide.html

            [[alternative HTML version deleted]]

Indeed!
I was just hoping that there would be a shorter way... intersect() is a
nice alternative too. Maybe I can make it work with pipes so that I
don't have to repeat "mydata" but that's another story.

Thank you for the help!
Ivan

--
Dr. Ivan Calandra
TraCEr, laboratory for Traceology and Controlled Experiments
MONREPOS Archaeological Research Centre and
Museum for Human Behavioural Evolution
Schloss Monrepos
56567 Neuwied, Germany
+49 (0) 2631 9772-243
https://www.researchgate.net/profile/Ivan_Calandra

On 19/08/2020 17:31, Bert Gunter wrote:

Well... wouldn't it be:

rep("(ConfoMap.*GuineaPigs)|(GuineaPigs.*ConfoMap)", mydata, value=TRUE)

Bert Gunter

"The trouble with having an open mind is that people keep coming along
and sticking things into it."
-- Opus (aka Berkeley Breathed in his "Bloom County" comic strip )


On Wed, Aug 19, 2020 at 8:23 AM Ivan Calandra <calandra at rgzm.de
<mailto:calandra at rgzm.de>> wrote:

    Thank you Bert for the pointer.

    So I guess the solution is:
    grep("ConfoMap.+GuineaPigs", mydata, value=TRUE)

    This is not the case here, but what if "GuineaPigs" comes before
    "ConfoMap"?
    Of course I could do two "grep()" calls, but if there a better
    solution?

    Ivan

    --
    Dr. Ivan Calandra
    TraCEr, laboratory for Traceology and Controlled Experiments
    MONREPOS Archaeological Research Centre and
    Museum for Human Behavioural Evolution
    Schloss Monrepos
    56567 Neuwied, Germany
    +49 (0) 2631 9772-243
    https://www.researchgate.net/profile/Ivan_Calandra

    On 19/08/2020 17:07, Bert Gunter wrote:

    > "&" is not a regex metacharacter.
    > See ?regexp
    >
    > Bert Gunter
    >
    > "The trouble with having an open mind is that people keep coming

    along

    > and sticking things into it."
    > -- Opus (aka Berkeley Breathed in his "Bloom County" comic strip )
    >
    >
    > On Wed, Aug 19, 2020 at 7:53 AM Ivan Calandra <calandra at rgzm.de

    <mailto:calandra at rgzm.de>

    > <mailto:calandra at rgzm.de <mailto:calandra at rgzm.de>>> wrote:
    >
    >     Dear useRs,
    >
    >     I feel really stupid, but I cannot understand why "&"

    doesn't work

    >     as I
    >     expect, while "|" does.
    >
    >     I have the following vector:
    >     mydata <- c("SSFA-ConfoMap_GuineaPigs_NMPfilled.csv",
    >     "SSFA-ConfoMap_Lithics_NMPfilled.csv",
    >     "SSFA-ConfoMap_Sheeps_NMPfilled.csv",
    >     "SSFA-Toothfrax_GuineaPigs.xlsx",
    >     "SSFA-Toothfrax_Lithics.xlsx", "SSFA-Toothfrax_Sheeps.xlsx")
    >     and I want to find the values that include both "ConfoMap" and
    >     "GuineaPigs".
    >
    >     If I do:
    >     grep("ConfoMap&GuineaPigs", mydata, value=TRUE)
    >     it returns an empty vector, character(0).
    >
    >     But if I do:
    >     grep("ConfoMap|GuineaPigs", mydata, value=TRUE)
    >     it returns all the elements that include either "ConfoMap" or
    >     "GuineaPigs", as I would expect.
    >
    >     So what is wrong with my "&" construct? How can I return the

    elements

    >     that include both parts?
    >
    >     Thank you for your help!
    >     Ivan
    >
    >     --
    >     Dr. Ivan Calandra
    >     TraCEr, laboratory for Traceology and Controlled Experiments
    >     MONREPOS Archaeological Research Centre and
    >     Museum for Human Behavioural Evolution
    >     Schloss Monrepos
    >     56567 Neuwied, Germany
    >     +49 (0) 2631 9772-243
    >     https://www.researchgate.net/profile/Ivan_Calandra
    >
    >     ______________________________________________
    >     R-help at r-project.org <mailto:R-help at r-project.org>

    <mailto:R-help at r-project.org <mailto:R-help at r-project.org>>
    mailing list --

    >     To UNSUBSCRIBE and more, see
    >     https://stat.ethz.ch/mailman/listinfo/r-help
    >     PLEASE do read the posting guide
    >     http://www.R-project.org/posting-guide.html

    code.

    >

foo <- c("a","b","cab","back")
foo[grepl("a",foo) & grepl("b",foo)]

Dear useRs,

I feel really stupid, but I cannot understand why "&" doesn't work as I
expect, while "|" does.

I have the following vector:
mydata <- c("SSFA-ConfoMap_GuineaPigs_NMPfilled.csv",
"SSFA-ConfoMap_Lithics_NMPfilled.csv",
"SSFA-ConfoMap_Sheeps_NMPfilled.csv", "SSFA-Toothfrax_GuineaPigs.xlsx",
"SSFA-Toothfrax_Lithics.xlsx", "SSFA-Toothfrax_Sheeps.xlsx")
and I want to find the values that include both "ConfoMap" and
"GuineaPigs".

If I do:
grep("ConfoMap&GuineaPigs", mydata, value=TRUE)
it returns an empty vector, character(0).

But if I do:
grep("ConfoMap|GuineaPigs", mydata, value=TRUE)
it returns all the elements that include either "ConfoMap" or
"GuineaPigs", as I would expect.

So what is wrong with my "&" construct? How can I return the elements
that include both parts?

Thank you for your help!
Ivan

--
Dr. Ivan Calandra
TraCEr, laboratory for Traceology and Controlled Experiments
MONREPOS Archaeological Research Centre and
Museum for Human Behavioural Evolution
Schloss Monrepos
56567 Neuwied, Germany
+49 (0) 2631 9772-243
https://www.researchgate.net/profile/Ivan_Calandra

There are & and | operators in the R language.
There is an | operator in regular expressions.
There is NOT any & operator in regular expressions.
grep("ConfoMap&GuineaPigs", mydata, value=TRUE)
looks for elements of mydata containing the literal
string 'ConfoMap&GuineaPigs'.

foo <- c("a","b","cab","back")
foo[grepl("a",foo) & grepl("b",foo)]

[1] "cab" ?"back"

grepl returns a TRUE/FALSE vector.

On Thu, 20 Aug 2020 at 02:53, Ivan Calandra <calandra at rgzm.de
<mailto:calandra at rgzm.de>> wrote:

    Dear useRs,

    I feel really stupid, but I cannot understand why "&" doesn't work
    as I
    expect, while "|" does.

    I have the following vector:
    mydata <- c("SSFA-ConfoMap_GuineaPigs_NMPfilled.csv",
    "SSFA-ConfoMap_Lithics_NMPfilled.csv",?
    "SSFA-ConfoMap_Sheeps_NMPfilled.csv",
    "SSFA-Toothfrax_GuineaPigs.xlsx",
    "SSFA-Toothfrax_Lithics.xlsx", "SSFA-Toothfrax_Sheeps.xlsx")
    and I want to find the values that include both "ConfoMap" and
    "GuineaPigs".

    If I do:
    grep("ConfoMap&GuineaPigs", mydata, value=TRUE)
    it returns an empty vector, character(0).

    But if I do:
    grep("ConfoMap|GuineaPigs", mydata, value=TRUE)
    it returns all the elements that include either "ConfoMap" or
    "GuineaPigs", as I would expect.

    So what is wrong with my "&" construct? How can I return the elements
    that include both parts?

    Thank you for your help!
    Ivan

    -- 
    Dr. Ivan Calandra
    TraCEr, laboratory for Traceology and Controlled Experiments
    MONREPOS Archaeological Research Centre and
    Museum for Human Behavioural Evolution
    Schloss Monrepos
    56567 Neuwied, Germany
    +49 (0) 2631 9772-243
    https://www.researchgate.net/profile/Ivan_Calandra

test <- test <- c("xyCz",

grep("(?=.*A)(?=.*B)(?=.*C)", test, perl = TRUE)

lookfor <- c("A","B","C")
notme <- paste0("[^",lookfor,"]*")
z <- paste0("(?=", notme, lookfor, notme, "$)",collapse = "")
grep(z, test, perl = TRUE)

Thank you all for all the very helpful answers!

Best,
Ivan

--
Dr. Ivan Calandra
TraCEr, laboratory for Traceology and Controlled Experiments
MONREPOS Archaeological Research Centre and
Museum for Human Behavioural Evolution
Schloss Monrepos
56567 Neuwied, Germany
+49 (0) 2631 9772-243
https://www.researchgate.net/profile/Ivan_Calandra

On 20/08/2020 3:28, Richard O'Keefe wrote:

There are & and | operators in the R language.
There is an | operator in regular expressions.
There is NOT any & operator in regular expressions.
grep("ConfoMap&GuineaPigs", mydata, value=TRUE)
looks for elements of mydata containing the literal
string 'ConfoMap&GuineaPigs'.

foo <- c("a","b","cab","back")
foo[grepl("a",foo) & grepl("b",foo)]

[1] "cab"  "back"

grepl returns a TRUE/FALSE vector.

On Thu, 20 Aug 2020 at 02:53, Ivan Calandra <calandra at rgzm.de
<mailto:calandra at rgzm.de>> wrote:

    Dear useRs,

    I feel really stupid, but I cannot understand why "&" doesn't work
    as I
    expect, while "|" does.

    I have the following vector:
    mydata <- c("SSFA-ConfoMap_GuineaPigs_NMPfilled.csv",
    "SSFA-ConfoMap_Lithics_NMPfilled.csv",
    "SSFA-ConfoMap_Sheeps_NMPfilled.csv",
    "SSFA-Toothfrax_GuineaPigs.xlsx",
    "SSFA-Toothfrax_Lithics.xlsx", "SSFA-Toothfrax_Sheeps.xlsx")
    and I want to find the values that include both "ConfoMap" and
    "GuineaPigs".

    If I do:
    grep("ConfoMap&GuineaPigs", mydata, value=TRUE)
    it returns an empty vector, character(0).

    But if I do:
    grep("ConfoMap|GuineaPigs", mydata, value=TRUE)
    it returns all the elements that include either "ConfoMap" or
    "GuineaPigs", as I would expect.

    So what is wrong with my "&" construct? How can I return the elements
    that include both parts?

    Thank you for your help!
    Ivan

    --
    Dr. Ivan Calandra
    TraCEr, laboratory for Traceology and Controlled Experiments
    MONREPOS Archaeological Research Centre and
    Museum for Human Behavioural Evolution
    Schloss Monrepos
    56567 Neuwied, Germany
    +49 (0) 2631 9772-243
    https://www.researchgate.net/profile/Ivan_Calandra

The single grep regex solutions offered to Ivan's problem were fine,
but do not readily generalize to the conjunction of multiple (>2, say)
regex patterns that can appear anywhere in a string and in any order.
However, note that this can easily be done using the Perl zero width
lookahead construction,? "(?=...)" .
e.g.

test <- test <- c("xyCz",

"xAyCz","xAyBzC","xCByAz","xACyB","BAyyC","CBxBAy")

## to search for strings contain "A", "B", & "C" in any order

grep("(?=.*A)(?=.*B)(?=.*C)", test, perl = TRUE)

[1] 3 4 5 6 7

Note that this matches on one or multiple instances of the patterns.
If one wants only exactly one instance of each conjunct,? then
something like this should do:

lookfor <- c("A","B","C")
notme <- paste0("[^",lookfor,"]*")
z <- paste0("(?=", notme, lookfor, notme, "$)",collapse = "")
grep(z, test, perl = TRUE)

[1] 3 4 5 6

Cheers,
Bert




On Wed, Aug 19, 2020 at 11:38 PM Ivan Calandra <calandra at rgzm.de
<mailto:calandra at rgzm.de>> wrote:

    Thank you all for all the very helpful answers!

    Best,
    Ivan

    --
    Dr. Ivan Calandra
    TraCEr, laboratory for Traceology and Controlled Experiments
    MONREPOS Archaeological Research Centre and
    Museum for Human Behavioural Evolution
    Schloss Monrepos
    56567 Neuwied, Germany
    +49 (0) 2631 9772-243
    https://www.researchgate.net/profile/Ivan_Calandra

    On 20/08/2020 3:28, Richard O'Keefe wrote:

    > There are & and | operators in the R language.
    > There is an | operator in regular expressions.
    > There is NOT any & operator in regular expressions.
    > grep("ConfoMap&GuineaPigs", mydata, value=TRUE)
    > looks for elements of mydata containing the literal
    > string 'ConfoMap&GuineaPigs'.
    >

    > > foo <- c("a","b","cab","back")
    > > foo[grepl("a",foo) & grepl("b",foo)]

    > [1] "cab" ?"back"
    >
    > grepl returns a TRUE/FALSE vector.
    >
    > On Thu, 20 Aug 2020 at 02:53, Ivan Calandra <calandra at rgzm.de

    <mailto:calandra at rgzm.de>

    > <mailto:calandra at rgzm.de <mailto:calandra at rgzm.de>>> wrote:
    >
    >? ? ?Dear useRs,
    >
    >? ? ?I feel really stupid, but I cannot understand why "&"

    doesn't work

    >? ? ?as I
    >? ? ?expect, while "|" does.
    >
    >? ? ?I have the following vector:
    >? ? ?mydata <- c("SSFA-ConfoMap_GuineaPigs_NMPfilled.csv",
    >? ? ?"SSFA-ConfoMap_Lithics_NMPfilled.csv",?
    >? ? ?"SSFA-ConfoMap_Sheeps_NMPfilled.csv",
    >? ? ?"SSFA-Toothfrax_GuineaPigs.xlsx",
    >? ? ?"SSFA-Toothfrax_Lithics.xlsx", "SSFA-Toothfrax_Sheeps.xlsx")
    >? ? ?and I want to find the values that include both "ConfoMap" and
    >? ? ?"GuineaPigs".
    >
    >? ? ?If I do:
    >? ? ?grep("ConfoMap&GuineaPigs", mydata, value=TRUE)
    >? ? ?it returns an empty vector, character(0).
    >
    >? ? ?But if I do:
    >? ? ?grep("ConfoMap|GuineaPigs", mydata, value=TRUE)
    >? ? ?it returns all the elements that include either "ConfoMap" or
    >? ? ?"GuineaPigs", as I would expect.
    >
    >? ? ?So what is wrong with my "&" construct? How can I return the

    elements

    >? ? ?that include both parts?
    >
    >? ? ?Thank you for your help!
    >? ? ?Ivan
    >
    >? ? ?--
    >? ? ?Dr. Ivan Calandra
    >? ? ?TraCEr, laboratory for Traceology and Controlled Experiments
    >? ? ?MONREPOS Archaeological Research Centre and
    >? ? ?Museum for Human Behavioural Evolution
    >? ? ?Schloss Monrepos
    >? ? ?56567 Neuwied, Germany
    >? ? ?+49 (0) 2631 9772-243
    >? ? ?https://www.researchgate.net/profile/Ivan_Calandra
    >
    >? ? ?______________________________________________
    >? ? ?R-help at r-project.org <mailto:R-help at r-project.org>

    <mailto:R-help at r-project.org <mailto:R-help at r-project.org>>
    mailing list --

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    code.

    >