First implementation of probing method

The code nows offer the possibility to obtain the distribution function
for a specific species in a 3D velocity grid at a determined position.

This is a simple method that just scatter the particles in one cell into
the velocity grid.

src/modules/moduleInput.f90

@@ -60,6 +60,11 @@ MODULE moduleInput
       CALL readGeometry(config)
       CALL checkStatus(config, "readGeometry")
 
+      !Read probes
+      CALL verboseError('Reading Probes...')
+      CALL readProbes(config)
+      CALL checkStatus(config, 'readProbes')
+
       !Read initial state for species
       CALL verboseError('Reading Initial state...')
       CALL readInitial(config)
@@ -903,6 +908,47 @@ MODULE moduleInput
 
     END SUBROUTINE readGeometry
 
+    SUBROUTINE readProbes(config)
+      USE moduleProbe
+      USE moduleErrors
+      USE json_module
+      IMPLICIT NONE
+
+      TYPE(json_file), INTENT(inout):: config
+      CHARACTER(:), ALLOCATABLE:: object
+      LOGICAL:: found
+      CHARACTER(2):: istring
+      INTEGER:: i
+      CHARACTER(:), ALLOCATABLE:: speciesName
+      REAL(8), ALLOCATABLE, DIMENSION(:):: r
+      REAL(8), ALLOCATABLE, DIMENSION(:):: v1, v2, v3
+      INTEGER, ALLOCATABLE, DIMENSION(:):: points
+      REAL(8):: timeStep
+
+      CALL config%info('output.probes', found, n_children = nProbes)
+
+      IF (found) ALLOCATE(probe(1:nProbes))
+
+      DO i = 1, nProbes
+        WRITE(iString, '(I2)') i
+        object = 'output.probes(' // trim(istring) // ')'
+
+        CALL config%get(object // '.species', speciesName, found)
+        CALL config%get(object // '.position', r, found)
+        CALL config%get(object // '.velocity_1', v1, found)
+        CALL config%get(object // '.velocity_2', v2, found)
+        CALL config%get(object // '.velocity_3', v3, found)
+        CALL config%get(object // '.points', points, found)
+        CALL config%get(object // '.timeStep', timeStep, found)
+
+        IF (ANY(points < 2)) CALL criticalError("Number of points in probe " // iString // " incorrect", 'readProbes')
+
+        CALL probe(i)%init(i, speciesName, r, v1, v2, v3, points, timeStep)
+
+      END DO
+
+    END SUBROUTINE readProbes
+
     SUBROUTINE readEMBoundary(config)
       USE moduleMesh
       USE moduleOutput
@@ -926,7 +972,7 @@ MODULE moduleInput
       IF (found) ALLOCATE(boundEM(1:nBoundaryEM))
       
       DO i = 1, nBoundaryEM
-        WRITE(istring, '(i2)') i
+        WRITE(istring, '(I2)') i
         object = 'boundaryEM(' // trim(istring) // ')'
 
         CALL config%get(object // '.type', boundEM(i)%typeEM, found)