From b096d37130b7f597e5e0ac377b24591282c66150 Mon Sep 17 00:00:00 2001
From: Gard Spreemann <gspreemann@gmail.com>
Date: Tue, 29 Mar 2016 13:05:25 +0200
Subject: Image data support.

---
 phstuff/diphawrapper.py | 30 ++++++++++++++++++++++++++++++
 1 file changed, 30 insertions(+)

diff --git a/phstuff/diphawrapper.py b/phstuff/diphawrapper.py
index f6ab403..45444c8 100644
--- a/phstuff/diphawrapper.py
+++ b/phstuff/diphawrapper.py
@@ -18,6 +18,7 @@ optionally manage running the DIPHA executable.
 # DIPHA header files.
 DIPHA_MAGIC = 8067171840
 DIPHA_WEIGHTED_BOUNDARY_MATRIX = 0
+DIPHA_IMAGE_DATA = 1
 DIPHA_PERSISTENCE_DIAGRAM = 2
 DIPHA_DISTANCE_MATRIX = 7
 DIPHA_SPARSE_DISTANCE_MATRIX = 8
@@ -148,8 +149,36 @@ def save_edge_list(fname, edge_list):
             for j in range(0, len(edge_list[i])):
                 f.write(struct.pack('<d', factor*edge_list[i][j][1]))
 
+def save_cubical(fname, complex):
+    """Save a (any-dimensional) array that will be interpreted as a
+    cubical complex with top-dimensional cells entering the filtration
+    at the scale given by the array values.
+
+    Parameters:
+    -----------
+    
+    fname: Name of file to write.
+
+    complex: Any-dimensional array with floating-point values giving
+    the filtration values of the top-dimensional cells.
+    
+    """
+
+    with open(fname, "wb") as f:
+        f.write(struct.pack("<q", DIPHA_MAGIC))
+        f.write(struct.pack("<q", DIPHA_IMAGE_DATA))
+        f.write(struct.pack("<q", np.product(complex.shape)))
+        f.write(struct.pack("<q", len(complex.shape)))
+        
+        for n in complex.shape:
+            f.write(struct.pack("<q", n))
+
+        for w in complex.flat:
+            f.write(struct.pack("<d", w))
+            
 
 def load_barcode(fname, top_dim = None):
+
     """Load a barcode as written by DIPHA.
 
     Parameters:
@@ -213,6 +242,7 @@ def save_text_barcode(fname, barcode):
                     f.write("%d %g %g\n" %(dim, interval.birth, interval.death))
                 else:
                     f.write("%d %g inf\n" %(dim, interval.birth))
+
     
 
 class DiphaRunner:
-- 
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