Parsing time in EFIT header (#8)

* Try harder to parse time out of EFIT header and giveup with a warning message if that still fails.

* Add set_time option to readg() as backup for failing to parse time in geqdsk

* if set_time is provided, use it instead of parsing

If set_time is provided, then it will be used and the code will not
attempt to parse the description line to find time in it. This
assumes that the user is setting time deliberately, so it should
override any other logic.

In case set_time is not provided, then parsing will be attempted but if
it fails, instead of just printing a warning, the code should throw an
error with the error message so that the code stops continuing further
and alerts the user about the issue.

* Broken (needs fix and cleanup): split header parsing into its own file and add test for header parsing

* parse header testing works now

The separated parse header function now works and is tested. To add
more tests, the header list can be expanded with other cases and
expected outcomes.

---------

Co-authored-by: Anchal Gupta <[email protected]>

Author: eldond

src/io.jl

@@ -66,20 +66,55 @@ function read_array2d(t,n,m)
     return data'
 end
 
-function readg(gfile)
+function parse_gfile_header(headerline::String; set_time=nothing)
+    s = split(headerline)
+
+    if !isnothing(set_time)
+        time = set_time
+    else
+        time = Meta.parse(s[end-3])
+        time_warning = "EFIT.jl could not convert time from ms (assumed units) to s"
+        omfit_advice = "Options for proceeding include:\n" *
+                       "i)    Editing the header in your gEQDSK file.\n" *
+                       "ii)   Trying to use OMFIT: python: `OMFITgeqdsk(file).to_omas().save('ods.jl')`\n" *
+                       "iii)  Set the time manually with the `set_time` keyword argument.\n"
+        try
+            time /= 1000.0  # Assume it was written in ms and convert to s
+        catch e
+            if time isa String
+                rg2 = r"([[:digit:]]+|(?:[[:punct:]]|[[:blank:]])+)"
+                try
+                    time = parse(Int, collect(eachmatch(rg2, time))[1][1]) / 1000.0
+                catch e
+                    error(
+                        time_warning,
+                        ", even after trying really hard with regex and everything.\nTime is ",
+                        time,
+                        ". \n",
+                        omfit_advice
+                    )
+                end
+            else
+                error(time_warning, ".\nTime is parsed as ", time," of type ", typeof(time), ". ", omfit_advice)
+            end
+        end
+    end
+
+    idum = Meta.parse(s[end-2])
+    nw = Meta.parse(s[end-1])
+    nh = Meta.parse(s[end])
+
+    return idum, time, nw, nh
+end
+
+function readg(gfile; set_time=nothing)
 
     isfile(gfile) || error("$(gfile) does not exist")
 
     f = open(gfile)
 
     desc = readline(f)
-    s = split(desc)
-
-    time = Meta.parse(s[end-3])
-    time /= 1000.0  # Assume it was written in ms and convert to s
-    idum = Meta.parse(s[end-2])
-    nw = Meta.parse(s[end-1])
-    nh = Meta.parse(s[end])
+    idum, time, nw, nh = parse_gfile_header(desc, set_time=set_time)
 
     token = file_numbers(f)
 

test/runtests.jl

@@ -1,5 +1,6 @@
 using Test
 using EFIT
+import EFIT
 
 g = readg(EFIT.test_gfile)
 g2 = readg(EFIT.test_gfile2)
@@ -58,3 +59,38 @@ lt, ut = triangularity(g)
     @test (xrs[2] > 1.2) & (xrs[2] < 1.33)
     @test (xzs[2] > 1.04) & (xzs[2] < 1.17)
 end
+
+@testset "parse header" begin
+    headers = [
+        "   EFITD    00/00/2008    #002296  0200ms Convert   0 257 513",
+        "   EFITD   11/23/2020    #184833  3600             3  65  65",
+    ]
+    times = [
+        0.2,
+        3.6,
+    ]
+    expect_exception = [
+        true,
+        false,
+    ]
+    the_set_time = 0.2
+    for set_time in [the_set_time, nothing]
+        for i in eachindex(headers)
+            try
+                idum, time, nw, nh = EFIT.parse_gfile_header(headers[i]; set_time=set_time)
+                if !isnothing(set_time)
+                    @test time == the_set_time
+                else
+                    @test time == times[i]
+                end
+            catch
+                if expect_exception[i]
+                    println("Got the expected exception")
+                else
+                    println("Got the unexpected exception")
+                end
+                @test expect_exception[i]
+            end
+        end
+    end
+end