To calculate magnetic declinations in B4A, I've been successfully using derez's Magnetics Library. In that thread, Erel provided an xMagnetics class in order to do the same thing in B4i and asked that it be tested. I finally tested it in my B4i application and unfortunately it crashed, generating this log message:
The crash happens in Line 33 of the class module, when assigning a value to SP(0):
Actually, any of the array initializations cause this problem. They are declared as:
So why would simply assigning values to these arrays cause this kind of a crash?
B4X:
Application_Start
Application_Active
Error occurred on line: 33 (XMagnetics)
Target is null. Method called: setObjectFastN::
Stack Trace: (
CoreFoundation <redacted> + 148
libobjc.A.dylib objc_exception_throw + 56
CoreFoundation <redacted> + 0
(myapp) +[B4I runDynamicMethod:method:throwErrorIfMissing:args:] + 192
(myapp) -[B4IShell runVoidMethod] + 232
(myapp) -[B4IShell raiseEventImpl:method:args::] + 1416
(myapp) -[B4IShellBI raiseEvent:event:params:] + 1408
(myapp) __24-[B4ITimer startTicking]_block_invoke + 332
libdispatch.dylib <redacted> + 16
libdispatch.dylib <redacted> + 428
libdispatch.dylib <redacted> + 1588
libdispatch.dylib <redacted> + 720
CoreFoundation <redacted> + 12
CoreFoundation <redacted> + 2012
CoreFoundation CFRunLoopRunSpecific + 436
GraphicsServices GSEventRunModal + 100
UIKit UIApplicationMain + 236
(myapp) main + 124
libdyld.dylib <redacted> + 4
)The crash happens in Line 33 of the class module, when assigning a value to SP(0):
B4X:
Private Sub DoInitialize
Dim lines As List = File.ReadList(File.DirAssets, "wmmc.cof")
Dim FirstLine() As String = Regex.Split(",", lines.Get(0))
EPOCH = FirstLine(0)
MAXORD = 12
DTR = cPI / 180
SP(0) = 0
CP(0) = 1
P(0, 0) = 1
PP(0) = 1
DP(0, 0) = 0
...Actually, any of the array initializations cause this problem. They are declared as:
B4X:
Private C(13, 13) As Double
Private CD(13, 13) As Double
Private P(13, 13) As Double
Private DP(13, 13) As Double
Private SNORM(13, 13) As Double
Private K(13, 13) As Double
Private SP(13) As Double
Private CP(13) As Double
Private FN(13) As Double
Private FM(13) As Double
Private PP(13) As DoubleSo why would simply assigning values to these arrays cause this kind of a crash?
