How to get a specific value out of a dataframe in R

up vote
0
down vote

favorite

I am trying to get the cp value for which my xerroris the smallest. I fitted a model like below and printed the cptable. Since the list is so long, I displayed only the first 20 rows.

>printcp(RT_model)



 Regression tree:

rpart(formula = BW ~ ., data = train, method = "anova", 

control = rpart.control(minsplit = 0, minbucket = 1, cp = -1))



Variables actually used in tree construction:

[1] age      black    boy      cigar    collgrad hsgrad   married  

natal2   natal3   nosmoke  novisit  somecoll wtgain  



Root node error: 5.2267e+10/159689 = 327304



n= 159689 



               CP nsplit rel error  xerror      xstd

1      4.3760e-02      0   1.00000 1.00001 0.0054277

2      1.6392e-02      1   0.95624 0.95661 0.0050844

3      1.1851e-02      2   0.93985 0.94067 0.0049671

4      1.1133e-02      3   0.92800 0.92446 0.0049150

5      1.0735e-02      4   0.91686 0.91709 0.0048956

6      6.1850e-03      5   0.90613 0.90692 0.0048695

7      3.3414e-03      6   0.89994 0.90054 0.0048561

8      2.6481e-03      7   0.89660 0.89680 0.0048502

9      2.4185e-03      8   0.89395 0.89441 0.0048449

10     2.1499e-03      9   0.89154 0.89232 0.0048248

11     2.0960e-03     10   0.88939 0.88993 0.0048055

12     1.3600e-03     11   0.88729 0.88822 0.0048031

13     1.3513e-03     12   0.88593 0.88616 0.0047898

14     1.2209e-03     13   0.88458 0.88600 0.0047862

15     9.2359e-04     14   0.88336 0.88454 0.0047731

16     9.1119e-04     15   0.88243 0.88364 0.0047679

17     7.8948e-04     16   0.88152 0.88300 0.0047662

18     7.4059e-04     17   0.88073 0.88221 0.0047638

19     6.8623e-04     18   0.87999 0.88142 0.0047610

20     6.7196e-04     19   0.87931 0.88077 0.0047620

...

[ erreichte getOption("max.print") --  25545 Zeilen ausgelassen ]

Since there are so many values:

To get the cpwith the smalles xerror, I use the following code:

   minCP <- RT_model$cptable[which.min(RT_model$cptable[,"xerror"]), "CP"]

The corresponding xerror of the minCP equals: 0.8690961 xerror

Now I want to apply a rule called "minimal xerror + standard deviation"

The corresponding standard deviation of minCP equals 0.004700524 xstd

I need the greatest value of the table that is equal or smaller than the new xerror called xerror_new (0.8690961 xerror + 0.004700524 xstd = 0.8737966). So I need the greatest value of the xerrorcolumn of the cptable which is less or equal to 0.8737966

How do I get the cp-value of the cptable which has an xerror smaller or equal to the xerror_newvalue of 0.8737966?

I tried the following but it failed hard.

  min_xerror <- RT_model$cptable[which.min(RT_model$cptable[,"xerror"]), 

  "xerror"]

this gave me the minimal xerrorin the table. And the following gives me the corresponding minimal xstd

   min_xstd <- RT_model$cptable[which.min(RT_model$cptable[,"xerror"]), "xstd"]

here I apply the "minimal xerror + standard deviation" rule:

  xerror_new <- min_xerror + min_xstd

up to here I get values and everything is fine. From here I struggle:

  xerror_plus_xstd <- RT_model$cptable[which.max(RT_model$cptable["xerror"<= 

  min_xerror_xstd] & RT_model$cptable["xerror" >= min_xerror]), "xerror"]

or I tried this:

 xerror_plus_xstd <- RT_model$cptable[which.max(RT_model$cptable["xerror"<= min_xerror_xstd]), "xerror"]

Both yield no result.

How can I get this value? Thanks.

edited Nov 22 at 9:19

desertnaut

15.7k53463

asked Nov 22 at 8:07

Milan Mitrovic

Question has nothing to do with machine-learning - kindly do not spam the tag (removed).
– desertnaut
Nov 22 at 9:19

1

My suggestion is that you use the broomstick package to convert the results into a data.frame and use dplyr to carry out the selection. You also coud share a reproducible example, so someone can help more effectively.
– José
Nov 22 at 9:50

add a comment |

up vote
0
down vote

favorite

I am trying to get the cp value for which my xerroris the smallest. I fitted a model like below and printed the cptable. Since the list is so long, I displayed only the first 20 rows.

>printcp(RT_model)



 Regression tree:

rpart(formula = BW ~ ., data = train, method = "anova", 

control = rpart.control(minsplit = 0, minbucket = 1, cp = -1))



Variables actually used in tree construction:

[1] age      black    boy      cigar    collgrad hsgrad   married  

natal2   natal3   nosmoke  novisit  somecoll wtgain  



Root node error: 5.2267e+10/159689 = 327304



n= 159689 



               CP nsplit rel error  xerror      xstd

1      4.3760e-02      0   1.00000 1.00001 0.0054277

2      1.6392e-02      1   0.95624 0.95661 0.0050844

3      1.1851e-02      2   0.93985 0.94067 0.0049671

4      1.1133e-02      3   0.92800 0.92446 0.0049150

5      1.0735e-02      4   0.91686 0.91709 0.0048956

6      6.1850e-03      5   0.90613 0.90692 0.0048695

7      3.3414e-03      6   0.89994 0.90054 0.0048561

8      2.6481e-03      7   0.89660 0.89680 0.0048502

9      2.4185e-03      8   0.89395 0.89441 0.0048449

10     2.1499e-03      9   0.89154 0.89232 0.0048248

11     2.0960e-03     10   0.88939 0.88993 0.0048055

12     1.3600e-03     11   0.88729 0.88822 0.0048031

13     1.3513e-03     12   0.88593 0.88616 0.0047898

14     1.2209e-03     13   0.88458 0.88600 0.0047862

15     9.2359e-04     14   0.88336 0.88454 0.0047731

16     9.1119e-04     15   0.88243 0.88364 0.0047679

17     7.8948e-04     16   0.88152 0.88300 0.0047662

18     7.4059e-04     17   0.88073 0.88221 0.0047638

19     6.8623e-04     18   0.87999 0.88142 0.0047610

20     6.7196e-04     19   0.87931 0.88077 0.0047620

...

[ erreichte getOption("max.print") --  25545 Zeilen ausgelassen ]

Since there are so many values:

To get the cpwith the smalles xerror, I use the following code:

   minCP <- RT_model$cptable[which.min(RT_model$cptable[,"xerror"]), "CP"]

The corresponding xerror of the minCP equals: 0.8690961 xerror

Now I want to apply a rule called "minimal xerror + standard deviation"

The corresponding standard deviation of minCP equals 0.004700524 xstd

How do I get the cp-value of the cptable which has an xerror smaller or equal to the xerror_newvalue of 0.8737966?

I tried the following but it failed hard.

  min_xerror <- RT_model$cptable[which.min(RT_model$cptable[,"xerror"]), 

  "xerror"]

this gave me the minimal xerrorin the table. And the following gives me the corresponding minimal xstd

   min_xstd <- RT_model$cptable[which.min(RT_model$cptable[,"xerror"]), "xstd"]

here I apply the "minimal xerror + standard deviation" rule:

  xerror_new <- min_xerror + min_xstd

up to here I get values and everything is fine. From here I struggle:

  xerror_plus_xstd <- RT_model$cptable[which.max(RT_model$cptable["xerror"<= 

  min_xerror_xstd] & RT_model$cptable["xerror" >= min_xerror]), "xerror"]

or I tried this:

 xerror_plus_xstd <- RT_model$cptable[which.max(RT_model$cptable["xerror"<= min_xerror_xstd]), "xerror"]

Both yield no result.

How can I get this value? Thanks.

edited Nov 22 at 9:19

desertnaut

15.7k53463

asked Nov 22 at 8:07

Milan Mitrovic

Question has nothing to do with machine-learning - kindly do not spam the tag (removed).
– desertnaut
Nov 22 at 9:19

1

My suggestion is that you use the broomstick package to convert the results into a data.frame and use dplyr to carry out the selection. You also coud share a reproducible example, so someone can help more effectively.
– José
Nov 22 at 9:50

add a comment |

up vote
0
down vote

favorite

I am trying to get the cp value for which my xerroris the smallest. I fitted a model like below and printed the cptable. Since the list is so long, I displayed only the first 20 rows.

>printcp(RT_model)



 Regression tree:

rpart(formula = BW ~ ., data = train, method = "anova", 

control = rpart.control(minsplit = 0, minbucket = 1, cp = -1))



Variables actually used in tree construction:

[1] age      black    boy      cigar    collgrad hsgrad   married  

natal2   natal3   nosmoke  novisit  somecoll wtgain  



Root node error: 5.2267e+10/159689 = 327304



n= 159689 



               CP nsplit rel error  xerror      xstd

1      4.3760e-02      0   1.00000 1.00001 0.0054277

2      1.6392e-02      1   0.95624 0.95661 0.0050844

3      1.1851e-02      2   0.93985 0.94067 0.0049671

4      1.1133e-02      3   0.92800 0.92446 0.0049150

5      1.0735e-02      4   0.91686 0.91709 0.0048956

6      6.1850e-03      5   0.90613 0.90692 0.0048695

7      3.3414e-03      6   0.89994 0.90054 0.0048561

8      2.6481e-03      7   0.89660 0.89680 0.0048502

9      2.4185e-03      8   0.89395 0.89441 0.0048449

10     2.1499e-03      9   0.89154 0.89232 0.0048248

11     2.0960e-03     10   0.88939 0.88993 0.0048055

12     1.3600e-03     11   0.88729 0.88822 0.0048031

13     1.3513e-03     12   0.88593 0.88616 0.0047898

14     1.2209e-03     13   0.88458 0.88600 0.0047862

15     9.2359e-04     14   0.88336 0.88454 0.0047731

16     9.1119e-04     15   0.88243 0.88364 0.0047679

17     7.8948e-04     16   0.88152 0.88300 0.0047662

18     7.4059e-04     17   0.88073 0.88221 0.0047638

19     6.8623e-04     18   0.87999 0.88142 0.0047610

20     6.7196e-04     19   0.87931 0.88077 0.0047620

...

[ erreichte getOption("max.print") --  25545 Zeilen ausgelassen ]

Since there are so many values:

To get the cpwith the smalles xerror, I use the following code:

   minCP <- RT_model$cptable[which.min(RT_model$cptable[,"xerror"]), "CP"]

The corresponding xerror of the minCP equals: 0.8690961 xerror

Now I want to apply a rule called "minimal xerror + standard deviation"

The corresponding standard deviation of minCP equals 0.004700524 xstd

How do I get the cp-value of the cptable which has an xerror smaller or equal to the xerror_newvalue of 0.8737966?

I tried the following but it failed hard.

  min_xerror <- RT_model$cptable[which.min(RT_model$cptable[,"xerror"]), 

  "xerror"]

this gave me the minimal xerrorin the table. And the following gives me the corresponding minimal xstd

   min_xstd <- RT_model$cptable[which.min(RT_model$cptable[,"xerror"]), "xstd"]

here I apply the "minimal xerror + standard deviation" rule:

  xerror_new <- min_xerror + min_xstd

up to here I get values and everything is fine. From here I struggle:

  xerror_plus_xstd <- RT_model$cptable[which.max(RT_model$cptable["xerror"<= 

  min_xerror_xstd] & RT_model$cptable["xerror" >= min_xerror]), "xerror"]

or I tried this:

 xerror_plus_xstd <- RT_model$cptable[which.max(RT_model$cptable["xerror"<= min_xerror_xstd]), "xerror"]

Both yield no result.

How can I get this value? Thanks.

edited Nov 22 at 9:19

desertnaut

15.7k53463

asked Nov 22 at 8:07

Milan Mitrovic

I am trying to get the cp value for which my xerroris the smallest. I fitted a model like below and printed the cptable. Since the list is so long, I displayed only the first 20 rows.

>printcp(RT_model)



 Regression tree:

rpart(formula = BW ~ ., data = train, method = "anova", 

control = rpart.control(minsplit = 0, minbucket = 1, cp = -1))



Variables actually used in tree construction:

[1] age      black    boy      cigar    collgrad hsgrad   married  

natal2   natal3   nosmoke  novisit  somecoll wtgain  



Root node error: 5.2267e+10/159689 = 327304



n= 159689 



               CP nsplit rel error  xerror      xstd

1      4.3760e-02      0   1.00000 1.00001 0.0054277

2      1.6392e-02      1   0.95624 0.95661 0.0050844

3      1.1851e-02      2   0.93985 0.94067 0.0049671

4      1.1133e-02      3   0.92800 0.92446 0.0049150

5      1.0735e-02      4   0.91686 0.91709 0.0048956

6      6.1850e-03      5   0.90613 0.90692 0.0048695

7      3.3414e-03      6   0.89994 0.90054 0.0048561

8      2.6481e-03      7   0.89660 0.89680 0.0048502

9      2.4185e-03      8   0.89395 0.89441 0.0048449

10     2.1499e-03      9   0.89154 0.89232 0.0048248

11     2.0960e-03     10   0.88939 0.88993 0.0048055

12     1.3600e-03     11   0.88729 0.88822 0.0048031

13     1.3513e-03     12   0.88593 0.88616 0.0047898

14     1.2209e-03     13   0.88458 0.88600 0.0047862

15     9.2359e-04     14   0.88336 0.88454 0.0047731

16     9.1119e-04     15   0.88243 0.88364 0.0047679

17     7.8948e-04     16   0.88152 0.88300 0.0047662

18     7.4059e-04     17   0.88073 0.88221 0.0047638

19     6.8623e-04     18   0.87999 0.88142 0.0047610

20     6.7196e-04     19   0.87931 0.88077 0.0047620

...

[ erreichte getOption("max.print") --  25545 Zeilen ausgelassen ]

Since there are so many values:

To get the cpwith the smalles xerror, I use the following code:

   minCP <- RT_model$cptable[which.min(RT_model$cptable[,"xerror"]), "CP"]

The corresponding xerror of the minCP equals: 0.8690961 xerror

Now I want to apply a rule called "minimal xerror + standard deviation"

The corresponding standard deviation of minCP equals 0.004700524 xstd

How do I get the cp-value of the cptable which has an xerror smaller or equal to the xerror_newvalue of 0.8737966?

I tried the following but it failed hard.

  min_xerror <- RT_model$cptable[which.min(RT_model$cptable[,"xerror"]), 

  "xerror"]

this gave me the minimal xerrorin the table. And the following gives me the corresponding minimal xstd

   min_xstd <- RT_model$cptable[which.min(RT_model$cptable[,"xerror"]), "xstd"]

here I apply the "minimal xerror + standard deviation" rule:

  xerror_new <- min_xerror + min_xstd

up to here I get values and everything is fine. From here I struggle:

  xerror_plus_xstd <- RT_model$cptable[which.max(RT_model$cptable["xerror"<= 

  min_xerror_xstd] & RT_model$cptable["xerror" >= min_xerror]), "xerror"]

or I tried this:

 xerror_plus_xstd <- RT_model$cptable[which.max(RT_model$cptable["xerror"<= min_xerror_xstd]), "xerror"]

Both yield no result.

How can I get this value? Thanks.

r dataframe

edited Nov 22 at 9:19

desertnaut

15.7k53463

asked Nov 22 at 8:07

Milan Mitrovic

edited Nov 22 at 9:19

desertnaut

15.7k53463

asked Nov 22 at 8:07

Milan Mitrovic

edited Nov 22 at 9:19

desertnaut

15.7k53463

edited Nov 22 at 9:19

desertnaut

15.7k53463

edited Nov 22 at 9:19

desertnaut

15.7k53463

asked Nov 22 at 8:07

Milan Mitrovic

asked Nov 22 at 8:07

Milan Mitrovic

asked Nov 22 at 8:07

Milan Mitrovic

Question has nothing to do with machine-learning - kindly do not spam the tag (removed).
– desertnaut
Nov 22 at 9:19

1

My suggestion is that you use the broomstick package to convert the results into a data.frame and use dplyr to carry out the selection. You also coud share a reproducible example, so someone can help more effectively.
– José
Nov 22 at 9:50

add a comment |

Question has nothing to do with machine-learning - kindly do not spam the tag (removed).
– desertnaut
Nov 22 at 9:19

1

My suggestion is that you use the broomstick package to convert the results into a data.frame and use dplyr to carry out the selection. You also coud share a reproducible example, so someone can help more effectively.
– José
Nov 22 at 9:50

Question has nothing to do with machine-learning - kindly do not spam the tag (removed).
– desertnaut
Nov 22 at 9:19

My suggestion is that you use the broomstick package to convert the results into a data.frame and use dplyr to carry out the selection. You also coud share a reproducible example, so someone can help more effectively.
– José
Nov 22 at 9:50

add a comment |

active

oldest

votes

Your Answer

StackExchange.ifUsing("editor", function () {
StackExchange.using("externalEditor", function () {
StackExchange.using("snippets", function () {
StackExchange.snippets.init();
});
});
}, "code-snippets");

StackExchange.ready(function() {
var channelOptions = {
tags: "".split(" "),
id: "1"
};
initTagRenderer("".split(" "), "".split(" "), channelOptions);

StackExchange.using("externalEditor", function() {
// Have to fire editor after snippets, if snippets enabled
if (StackExchange.settings.snippets.snippetsEnabled) {
StackExchange.using("snippets", function() {
createEditor();
});
}
else {
createEditor();
}
});

function createEditor() {
StackExchange.prepareEditor({
heartbeatType: 'answer',
convertImagesToLinks: true,
noModals: true,
showLowRepImageUploadWarning: true,
reputationToPostImages: 10,
bindNavPrevention: true,
postfix: "",
imageUploader: {
brandingHtml: "Powered by u003ca class="icon-imgur-white" href="https://imgur.com/"u003eu003c/au003e",
contentPolicyHtml: "User contributions licensed under u003ca href="https://creativecommons.org/licenses/by-sa/3.0/"u003ecc by-sa 3.0 with attribution requiredu003c/au003e u003ca href="https://stackoverflow.com/legal/content-policy"u003e(content policy)u003c/au003e",
allowUrls: true
},
onDemand: true,
discardSelector: ".discard-answer"
,immediatelyShowMarkdownHelp:true
});

}
});

draft saved

draft discarded

Sign up or log in

StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});

Post as a guest

Name

Required, but never shown

StackExchange.ready(
function () {
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fstackoverflow.com%2fquestions%2f53426368%2fhow-to-get-a-specific-value-out-of-a-dataframe-in-r%23new-answer', 'question_page');
}
);

Post as a guest

Name

Required, but never shown

active

oldest

votes

draft saved

draft discarded

Thanks for contributing an answer to Stack Overflow!

Please be sure to answer the question. Provide details and share your research!

But avoid …

Asking for help, clarification, or responding to other answers.

Making statements based on opinion; back them up with references or personal experience.

To learn more, see our tips on writing great answers.

Some of your past answers have not been well-received, and you're in danger of being blocked from answering.

Please pay close attention to the following guidance:

Please be sure to answer the question. Provide details and share your research!

But avoid …

Asking for help, clarification, or responding to other answers.

Making statements based on opinion; back them up with references or personal experience.

To learn more, see our tips on writing great answers.

draft saved

draft discarded

Sign up or log in

StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});

Post as a guest

Name

Required, but never shown

Post as a guest

Name

Required, but never shown

Sign up or log in

StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});

Post as a guest

Name

Required, but never shown

Sign up or log in

StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});

Post as a guest

Name

Required, but never shown

Sign up or log in

StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});

Post as a guest

Name

Required, but never shown

Name

Required, but never shown

Name

Required, but never shown

This page is only for reference, If you need detailed information, please check here

搜尋此網誌

Qfyilyi