如何读取坐标 csv 文件并分解为 E、N、Z 和 Station？

Posted 2023-04-14

【中文标题】如何读取坐标 csv 文件并分解为 E、N、Z 和 Station？

【英文标题】：How do I read a coordinate csv file and break into E,N,Z and Station?

【发布时间】：2020-09-03 06:38:32

【问题描述】：

如何读取 csv 文件并将 Northing、Easting、RL 和 StationName 放入单独的变量中，以便稍后在代码中调用？

...line3="$STN1"  
line4="$E1"  
line5="$N1"  
line6="$Z1"  
line7="$STN2"  
line8="$E2"  
line9="$N2"  
line10="$Z2"...

我正在使用一个名为 Surpac 的程序，它使用 TCL/SCL（Surpac 命令语言）作为内部语言来运行宏，所以我不确定如何让 tcllib CSV 为这个工作，所以我想知道如果有更原生的版本。

我有一个这样的文件；

标题（忽略） 起始线（忽略） stringno, Northing, Easting, RL, StationName, other, crap, I, don't, care, about stringno, Northing, Easting, RL, StationName, other, crap, I, don't, care, about SegmentBreak (0,0,0,0) Stringno、Northing、Easting、RL、StationName、... SegmentBreak (0,0,0,0) 文件结尾 (0, 0.000, 0.000, 0.000, END)

示例文件；

标题，x，y，z 0, 0.000, 0.000, 0.000, 0 1, 1724649.512, 124030.344, 139.540, 120100-01,58,0.0159,0.0128,0.0024 1、1724767.644、125844.370、107.213、12100-13,68,0.0108,0.009,0.0026 ...... 1、1724815.346、1285816.668、99.484、12000-14,70,0.0113,0.0092,0.0026 1, 1724797.046, 125785.089, 90.848, 12000-16,87,0.0127,0.009,0.0027 0, 0.000, 0.000, 0.000, 1、1725028.806、125903.122、-1318.821、SD152,2038,0.0154,0.0124,0.0097 1, 1725028.899, 125901.241, -1322.790, 857002,2039,0.0156,0.0125,0.0098 0, 0.000, 0.000, 0.000, 0, 0.000, 0.000, 0.000, 结束

就编程而言，我是个 hack 并且需要帮助，所以到目前为止我有这个。这是废话，但只是一个开始。

set stnfile [open $csvfile r]  
gets $stnfile header  
gets $stnfile nosence  
gets $stnfile STN1  
gets $stnfile STN2..... 

毫不奇怪，这只是将每一行作为变量：STNx

【参考方案1】：

如果您无法安装并运行 tcllib，对于像这样的简单数据，可以使用 split 将一行分成一个列表：

set stnfile [open $csvfile r]
# Read and discard the first two lines
gets $stnfile
gets $stnfile
# Read the rest in a loop
while [gets $stnfile line] > 0] 
    # Split on comma and assign the first five elements to variables
    lassign [split $line ,] stringno northing easting rl stationname
    # Exit on END - beware of the leading space!
    if $stationname eq " END"  break 
    # Check for a segment break
    if $stringno == 0 && $northing == 0 && $easting == 0 && $rl == 0 
        # Do something with a break line?
     else 
        # Do something else with a regular line?
    

close $stnfile

【讨论】：

感谢肖恩的帮助，也感谢您的帮助！我调整了代码，它运行良好。原来 break 导致宏刚刚结束，所以我用if $stationname eq " END" set N1 "" set E1 "" set Z1 "" set S1 "" 替换了“break”我还拉出循环来分别定义每个变量。这样做的原因是我只有 22 个空格要填充，因此读取每一行不会使代码变长，并且我需要稍后同时调用每个变量。我真的不知道如何使用循环

【参考方案2】：

要读取 CSV 文件，请使用 Tcllib 中的 csv package。

package require struct::matrix
package require csv

# To hold the data we've read in
struct::matrix Data

# Do the read of the file. Note that you want mode 'auto' here
set f [open "input.csv"]
csv::read2matrix $f Data "," auto
close $f

现在我们可以处理Data：

# Remove the header rows
Data delete row 0
Data delete row 0;  # NB: second row has moved up one

# Remove the footer row
Data delete rows 1

# Go over the rows that remain:
for set r 0 $r < [Data rows] incr r 
    # Split the first bits of the row into variables; drops junk on end of line
    lassign [Data get row $r] stringno Northing Easting RL StationName
    # Skip zero lines
    if !$Northing && !$Easting && !$RL 
        continue
    
    # Do stuff with the row; I'm just printing things because I don't know what else...
    puts "($Northing,$Easting,$RL) --> $StationName"