[R] how to manage missing values correctly when importing a data frame

[PIKAL Petr]

Hi

Although you did not present your data in suitable format I do not see any problem.

See in line

> -----Original Message-----
> From: R-help [mailto:r-help-bounces at r-project.org] On Behalf Of Stefano
> Sofia
> Sent: Wednesday, September 7, 2016 1:09 PM
> To: r-help at r-project.org
> Subject: [R] how to manage missing values correctly when importing a data
> frame
>
> Dear R users,
> I have a data frame with 22 columns, called Storia_RM_RT. Here the first 4
> rows:
>
> Station_RM Sensor_RM Place_RM Y_init_RM M_init_RM D_init_RM
> Long_cent_RM Lat_cent_RM Height_RM Continues Station_RT Sensor_RT
> Place_RT Name1_RT Name2_RT Long_cent_RT Lat_cent_RT Height_RT
> Actual_net Notes Test_20141231 Test_20151231
> 1400 2701 Novafeltria 1959 1 1 12.289552 43.890057 293 NO NA NA NA NA NA
> NA NA NA CAE NA NO NO
> 1460 2702 Carpegna 1963 1 1 12.332614 43.778107 748 SI 702 2954 Carpegna
> Carpegna Carpegna 12.340618 43.780575 715 RT NA NO NO
> 1500 2703 Pesaro 1957 1 1 12.909822 43.910889 11 SI 112 1229 Pesaro
> Villa_Fastiggi Villa_Fastiggi 12.86939 43.890610 22 RT NA YES YES
> 1520 2704 Fano 1957 1 1 13.017591 43.840054 4 SI 152 2671 Fano
> Foce_Metauro Metaurilia 13.053796 43.826328 7.12 RT NA YES YES
>
> I load it with
> Storia_RM_RT <- read.table(file="Storia_RM_RT.txt", header = TRUE, sep="
> ", dec = ".", stringsAsFactors = FALSE)
>
> print(Storia_RM_RT$Test_20151231[Storia_RM_RT$Station_RM == 1500])
> gives [1] "YES"

So you have unique value here

>
> while
> print(Storia_RM_RT$Omogenea_20151231[Storia_RM_RT$Station_RT ==
> 112]) gives
> [1] NA   "YES"

and two values here, one is NA

see

dat<-data.frame(x1=c("a", "a", "b", NA), x2=c(1,2,3,3))
dat$x1<-as.character(dat$x1)

> dat$x1[dat$x2==1]
[1] "a"
> dat$x1[dat$x2==2]
[1] "a"
> dat$x1[dat$x2==3]
[1] "b" NA
>

You should consult R intro to understand basic object types, their distinctions and language basics.

Cheers
Petr


>
>
> print(lapply(Storia_RM_RT, class)) gives
>
> $Station_RM
> [1] "integer"
>
> $Sensor_RM
> [1] "integer"
>
> $Place_RM
> [1] "character"
>
> $Y_init_RM
> [1] "integer"
>
> $M_init_RM
> [1] "integer"
>
> $D_init_RM
> [1] "integer"
>
> $Long_cent_RM
> [1] "numeric"
>
> $Lat_cent_RM
> [1] "numeric"
>
> $Height_RM
> [1] "integer"
>
> $Continues
> [1] "character"
>
> $Station_RT
> [1] "integer"
>
> $Sensor_RT
> [1] "integer"
>
> $Place_RT
> [1] "character"
>
> $Name1_RT
> [1] "character"
>
> $Name2_RT
> [1] "character"
>
> $Long_cent_RT
> [1] "numeric"
>
> $Lat_cent_RT
> [1] "numeric"
> $Quota_RT
> [1] "numeric"
>
> $Actual_net
> [1] "character"
>
> $Notes
> [1] "logical"
>
> $Test_20141231
> [1] "character"
>
> $Test_20151231
> [1] "character"
>
> I am struggling to understand why the query through the field Station_RT
> does not work.
> Could please somebody help me to manage correctly the missing values? Is
> the mistake somewhere else?
>
> Thank you
> Stefano Sofia
>
>
> ________________________________
>
> AVVISO IMPORTANTE: Questo messaggio di posta elettronica può contenere
> informazioni confidenziali, pertanto è destinato solo a persone autorizzate
> alla ricezione. I messaggi di posta elettronica per i client di Regione Marche
> possono contenere informazioni confidenziali e con privilegi legali. Se non si è
> il destinatario specificato, non leggere, copiare, inoltrare o archiviare questo
> messaggio. Se si è ricevuto questo messaggio per errore, inoltrarlo al
> mittente ed eliminarlo completamente dal sistema del proprio computer. Ai
> sensi dell’art. 6 della DGR n. 1394/2008 si segnala che, in caso di necessità ed
> urgenza, la risposta al presente messaggio di posta elettronica può essere
> visionata da persone estranee al destinatario.
> IMPORTANT NOTICE: This e-mail message is intended to be received only by
> persons entitled to receive the confidential information it may contain. E-mail
> messages to clients of Regione Marche may contain information that is
> confidential and legally privileged. Please do not read, copy, forward, or store
> this message unless you are an intended recipient of it. If you have received
> this message in error, please forward it to the sender and delete it
> completely from your computer system.
>
>       [[alternative HTML version deleted]]
>
> ______________________________________________
> 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
> and provide commented, minimal, self-contained, reproducible code.

________________________________
Tento e-mail a jakékoliv k němu připojené dokumenty jsou důvěrné a jsou určeny pouze jeho adresátům.
Jestliže jste obdržel(a) tento e-mail omylem, informujte laskavě neprodleně jeho odesílatele. Obsah tohoto emailu i s přílohami a jeho kopie vymažte ze svého systému.
Nejste-li zamýšleným adresátem tohoto emailu, nejste oprávněni tento email jakkoliv užívat, rozšiřovat, kopírovat či zveřejňovat.
Odesílatel e-mailu neodpovídá za eventuální škodu způsobenou modifikacemi či zpožděním přenosu e-mailu.

V případě, že je tento e-mail součástí obchodního jednání:
- vyhrazuje si odesílatel právo ukončit kdykoliv jednání o uzavření smlouvy, a to z jakéhokoliv důvodu i bez uvedení důvodu.
- a obsahuje-li nabídku, je adresát oprávněn nabídku bezodkladně přijmout; Odesílatel tohoto e-mailu (nabídky) vylučuje přijetí nabídky ze strany příjemce s dodatkem či odchylkou.
- trvá odesílatel na tom, že příslušná smlouva je uzavřena teprve výslovným dosažením shody na všech jejích náležitostech.
- odesílatel tohoto emailu informuje, že není oprávněn uzavírat za společnost žádné smlouvy s výjimkou případů, kdy k tomu byl písemně zmocněn nebo písemně pověřen a takové pověření nebo plná moc byly adresátovi tohoto emailu případně osobě, kterou adresát zastupuje, předloženy nebo jejich existence je adresátovi či osobě jím zastoupené známá.

This e-mail and any documents attached to it may be confidential and are intended only for its intended recipients.
If you received this e-mail by mistake, please immediately inform its sender. Delete the contents of this e-mail with all attachments and its copies from your system.
If you are not the intended recipient of this e-mail, you are not authorized to use, disseminate, copy or disclose this e-mail in any manner.
The sender of this e-mail shall not be liable for any possible damage caused by modifications of the e-mail or by delay with transfer of the email.

In case that this e-mail forms part of business dealings:
- the sender reserves the right to end negotiations about entering into a contract in any time, for any reason, and without stating any reasoning.
- if the e-mail contains an offer, the recipient is entitled to immediately accept such offer; The sender of this e-mail (offer) excludes any acceptance of the offer on the part of the recipient containing any amendment or variation.
- the sender insists on that the respective contract is concluded only upon an express mutual agreement on all its aspects.
- the sender of this e-mail informs that he/she is not authorized to enter into any contracts on behalf of the company except for cases in which he/she is expressly authorized to do so in writing, and such authorization or power of attorney is submitted to the recipient or the person represented by the recipient, or the existence of such authorization is known to the recipient of the person represented by the recipient.