From 01c9bf2018824aced35d0d6719db07509e27497d Mon Sep 17 00:00:00 2001
From: Yggdrasil <yggdrasil@massaman-labs.de>
Date: Mon, 27 Apr 2026 17:27:02 +0200
Subject: [PATCH] Added read histogram subroutine. Started work on hist merge
 utility.

---
 Makefile       |  27 ++++++++-----
 event2_merge.f |   6 +++
 gbook.f        | 101 ++++++++++++++++++++++++++++++++++++++++++++-----
 3 files changed, 115 insertions(+), 19 deletions(-)
 create mode 100644 event2_merge.f

diff --git a/Makefile b/Makefile
index d4ea188..3285b70 100644
--- a/Makefile
+++ b/Makefile
@@ -14,22 +14,29 @@ endif
 # Output folder
 OUT = bin
 
-# Target executable
-TARGET = event2
+# Targets
+TARGET1 = event2
+TARGET2 = event2_merge
 
 # Source files
-SRCS = event2_03.f gbook.f
+SRCS1 = event2_03.f gbook.f
+SRCS2 = event2_merge.f gbook.f
 
-# Executable path
-EXE = $(OUT)/$(TARGET)
+# Executable paths
+EXE1 = $(OUT)/$(TARGET1)
+EXE2 = $(OUT)/$(TARGET2)
 
-# Default rule
-all: $(EXE)
+# Default rule (build both)
+all: $(EXE1) $(EXE2)
 
-# Build rule
-$(EXE): $(SRCS)
+# Build rules
+$(EXE1): $(SRCS1)
 	mkdir -p $(OUT)
-	$(FC) $(FFLAGS) -o $(EXE) $(SRCS)
+	$(FC) $(FFLAGS) -o $(EXE1) $(SRCS1)
+
+$(EXE2): $(SRCS2)
+	mkdir -p $(OUT)
+	$(FC) $(FFLAGS) -o $(EXE2) $(SRCS2)
 
 # Convenience targets
 debug:
diff --git a/event2_merge.f b/event2_merge.f
new file mode 100644
index 0000000..5fdec9b
--- /dev/null
+++ b/event2_merge.f
@@ -0,0 +1,6 @@
+      PROGRAM MAIN
+      CALL GREAD('./results/gtopdraw_THRUST_00000.dat')
+      CALL GTOPER(   3,1,1,0,100+3)
+      CALL GTOPER(10+3,0,0,0,110+3)
+      END PROGRAM
+C-----------------------------------------------------------------------
\ No newline at end of file
diff --git a/gbook.f b/gbook.f
index d5740c1..943d9a0 100644
--- a/gbook.f
+++ b/gbook.f
@@ -743,6 +743,12 @@ C  SET UP PAGE...
       ENDIF
       NTYPE=MOD(NTYPE,4)+1
 C  PLOT...
+      WRITE (21,*) 'HIST ID ',ID
+      IF (IDERR.NE.0) THEN
+         WRITE (21,*) 'HIST IDERR',IDERR
+      ENDIF
+      WRITE (21,*) 'HIST NBINS',NX
+      WRITE (21,*) 'DATA'
       DO 200 I=1, NX
          IF ((ABS(X(I)).GE.1E-3.AND.ABS(X(I)).LT.1E5.OR.X(I).EQ.0).AND.
      &       (ABS(Y(I)).GE.1E-5.AND.ABS(Y(I)).LT.1E3.OR.Y(I).EQ.0)) THEN
@@ -925,6 +931,91 @@ C-----------------------------------------------------------------------
          GOTO 200
       ENDIF
       END
+C-----------------------------------------------------------------------
+      SUBROUTINE GREAD(FILE)
+      IMPLICIT INTEGER (I-N)
+      IMPLICIT DOUBLE PRECISION (A-H,O-Z)
+
+      CHARACTER*(*) FILE
+      CHARACTER*200 LINE, TITLE
+      CHARACTER*100 KEYS(5)
+      DOUBLE PRECISION TX, TY, TE
+
+      PARAMETER (NSIZE=200000, NMAX=2000)
+      COMMON /GBOOK/ A(NSIZE)
+
+      INTEGER NX, IOS, ID, IDERR
+      LOGICAL INDATA
+
+      INDATA = .FALSE.
+      IDERR = 0
+
+      OPEN(10, FILE=FILE, STATUS='OLD')
+
+ 10   CONTINUE
+      READ(10,'(A)',END=900) LINE
+
+C --- Read keywords
+      READ(LINE,*,IOSTAT=IOS) KEYS
+
+      IF (IOS.GT.0) GOTO 10      
+
+C --- PROCESS KEYS
+      IF (KEYS(1).EQ.'SET') THEN
+         
+         IF(KEYS(2).EQ.'LIMITS') THEN
+            READ(KEYS(4),*) XMIN
+            READ(KEYS(5),*) XMAX
+         ENDIF
+
+      ELSE IF (KEYS(1).EQ.'TITLE') THEN
+         TITLE = KEYS(3)
+
+      ELSE IF (KEYS(1).EQ.'HIST') THEN
+
+         IF(KEYS(2).EQ.'ID') THEN
+            READ(KEYS(3),'(I4)') ID
+         ELSE IF(KEYS(2).EQ.'IDERR') THEN
+            READ(KEYS(3),'(I4)') IDERR
+         ELSE IF(KEYS(2).EQ.'NBINS') THEN
+            READ(KEYS(3),'(I4)') NX
+         ENDIF
+
+      ELSE IF (KEYS(1).EQ.'DATA') THEN
+         INDATA = .TRUE.
+         CALL GBOOK1(ID,TITLE,NX,XMIN,XMAX)
+         IF(IDERR.NE.0) THEN
+            CALL GBOOK1(IDERR,TITLE,NX,XMIN,XMAX)
+         ENDIF
+
+C --- DATA LINES
+      ELSE IF (INDATA) THEN
+
+         READ(LINE,*,IOSTAT=IOS) TX, TY, TE
+
+         IF(IOS.EQ.0) THEN
+            CALL GFILL1(ID,TX,TY)
+            IF(IDERR.NE.0) THEN
+               CALL GFILL1(IDERR,TX,TE)
+            ENDIF
+         ELSE IF (IOS .EQ. 5010) THEN
+C ------ FORMAT ERROR: CHECK IF END OF DATA OR JUST AN ERROR
+            IF(TRIM(LINE).EQ.'HIST          ; PLOT'.OR.
+     $          TRIM(LINE).EQ.'JOIN DASH     ; PLOT') THEN
+               INDATA = .FALSE.
+            ENDIF
+            GOTO 10
+         ENDIF
+
+      ENDIF
+
+      GOTO 10
+
+ 900  CONTINUE
+      CLOSE(10)
+
+      RETURN
+      END
 C-----------------------------------------------------------------------
       SUBROUTINE GOPENF
 C---OPEN TopDrawer FILE
@@ -935,6 +1026,7 @@ C---OPEN TopDrawer FILE
       COMMON /GFILE/ OPEN, TITLE
       COMMON /FPATH/ OPATH
       DATA OPEN/.FALSE./
+      DATA OPATH/'./'/
       IF (OPEN) RETURN
       OPEN=.TRUE.
       N=0
@@ -968,13 +1060,4 @@ C-----------------------------------------------------------------------
       COMMON /GTCOM/ TYPE,NTYPE
       DATA TYPE,NTYPE/'        ','DASH    ','DOT-DASH','PATTERN ',0/
       END
-C-----------------------------------------------------------------------
-      double precision function ran(iseed)
-      implicit none
-      integer iseed
-      double precision r(1)
-      call rangen(1,r)
-      iseed=iseed+1
-      ran=r(1)
-      end
 C-----------------------------------------------------------------------