Question

首先，我是编程的新手，所以这可能是一个简单的问题，但我无法在任何地方找到解决方案。

我一直在使用此代码从一组堆叠的栅格中提取值：

raster.files <- list.files() 
raster.list <- list()
raster.files <-list.files(".",pattern ="asc")

for(i in 1: length(raster.files)){
raster.list[i] <- raster(raster.files[i])}

stacking <- stack(raster.list)
coord <- read.csv2("...")
extract.data <- extract(stacking,coord,method="simple")

到目前为止，我已经多次使用过此代码而没有任何问题。每次运行提取行时，都会出现此错误：

Error in .doCellFromXY(object@ncols, object@nrows, object@extent@xmin,  : 
  Not compatible with requested type: [type=character; target=double].

coord文件包含一个包含2列（分别为X和Y）的data.frame。

Answer 1

我设法找到了一种绕过这个错误的方法，它在技术上并不是一个解决方案，因为我无法理解为什么R在第一时间将我的数据视为文本。

基本上我将X和Y列分开并单独处理它们，然后再将它们绑定在一个新的data.frame中：

  create or replace PACKAGE BODY gecm_t360_po_extraction_pk
ASPROCEDURE gecm_po_extraction_prc(
    p_errbuf OUT VARCHAR2,
    p_retcode OUT VARCHAR2,
    p_from_date IN VARCHAR2,
    p_to_date   IN VARCHAR2 )
IS

TYPE g_po_outbond_feed_rec
IS
  RECORD
  (
    po_number po_headers_all.segment1%TYPE,
    vendor_number ap_suppliers.segment1%TYPE,
    vendor_name ap_suppliers.vendor_name%TYPE,
    vendor_site ap_supplier_sites_all.vendor_site_code%TYPE,
    );

TYPE g_po_outbond_feed_table
IS
  TABLE OF g_po_outbond_feed_rec;
  g_po_outbond_feed_tbl g_po_outbond_feed_table;


  --
  v_legal_entity_name xle_entity_profiles.name%TYPE;
  v_segment_val gl_code_combinations.segment1%TYPE;
  v_req_distribution_id po_distributions_all.req_distribution_id%TYPE;
  v_requisition_num po_requisition_headers_all.segment1%TYPE;
  v_requestor_emp_num po_requisition_lines_all.to_person_id%TYPE;
  v_requestor_sso_id per_all_people_f.employee_number%TYPE;
  v_preparer_emp_num po_requisition_headers_all.preparer_id%TYPE;
  v_preparer_sso_id per_all_people_f.employee_number%TYPE;
  -- Start of changes as per v1.7
/*v_directory gecm_intf_param_tbl.parameter_value%TYPE;
  v_file_name gecm_intf_param_tbl.parameter_value%TYPE; */
  v_directory  VARCHAR2(4000);
  v_file_name  VARCHAR2(4000);
  -- End of changes as per v1.7
  v_from_date DATE;
  v_to_date DATE;
  --
  --Version 1.1 Code Changes Start
  v_process_control_id NUMBER;
  v_legal_entity_id    NUMBER;
  v_ledger_id          NUMBER;
  --Version 1.1 Code Changes End
  v_filehandle UTL_FILE.FILE_TYPE;
  p_record VARCHAR2(32000);

BEGIN


 fnd_date.initialize('YYYY/MM/DD', 'YYYY/MM/DD HH24:MI:SS');
  v_from_date := fnd_date.displayDT_to_date(p_from_date);
  v_to_date   := fnd_date.displayDT_to_date(p_to_date);

BEGIN

v_file_name := <getting file name>

EXCEPTION
  WHEN OTHERS THEN
    v_file_name:=NULL;
    g_message  := 'WHEN OTHERS: '||SQLERRM;
    apps.fnd_file.put_line(apps.fnd_file.log,g_message);
    p_retcode:=2;
END;

BEGIN
v_directory := <getting directory>
EXCEPTION
  WHEN OTHERS THEN
    v_directory:=NULL;
    g_message  := 'WHEN OTHERS: '||SQLERRM;
    apps.fnd_file.put_line(apps.fnd_file.log,g_message);
    p_retcode:=2;

END;
IF v_file_name IS NOT NULL AND v_directory IS NOT NULL THEN
    --
    BEGIN

SELECT * BULK COLLECT
      INTO g_po_outbond_feed_tbl
      FROM
        (SELECT poha.segment1                                                              

           AS po_number,
          aps.segment1                                                                     

           AS vendor_number,
          aps.vendor_name                                                                  

           AS vendor_name,
          apss.vendor_site_code                                                            

           AS vendor_site,
from 
<tables>
--------------------------------
BEGIN
        --
        IF g_po_outbond_feed_tbl.COUNT < 1 THEN
          g_message                   :='There is no POs to extract and file would not be 

generated if there is no POs';
          apps.fnd_file.put_line(apps.fnd_file.log,g_message);
        ELSE

v_filehandle := UTL_FILE.FOPEN(v_directory, v_file_name, 'W',32767);
p_record:='PO_NUMBER|VENDOR_NUMBER|VENDOR_NAME|VENDOR_SITE|VENDOR_SITE_CODE';
UTL_FILE.PUT_LINE(v_filehandle, p_record);
FOR i IN g_po_outbond_feed_tbl.FIRST .. g_po_outbond_feed_tbl.LAST
LOOP

p_record:=NVL(g_po_outbond_feed_tbl(i).po_number,'');
            p_record:=p_record||'|'||NVL(g_po_outbond_feed_tbl(i).vendor_number,'');
            p_record:=p_record||'|'||NVL(g_po_outbond_feed_tbl(i).vendor_name,'');
            p_record:=p_record||'|'||NVL(g_po_outbond_feed_tbl(i).vendor_site,'');
            p_record:=p_record||'|'||NVL(g_po_outbond_feed_tbl(i).vendor_site_code,'');

UTL_FILE.PUT_LINE(v_filehandle, p_record);

END LOOP;
END IF;

这是最优雅的方式，但它只是有效。

R extract（）不接受我的坐标

1 个答案: