--- /dev/null
+#
+# This file contains density values (2) against temperature (1) of a
+# common liquid crytsal (MBBA). At about 45.6 degr. there occurs a
+# phase transition indicated by the anomaly.
+#
+# Columns (3) and (4) contain weights for a straight line fit
+# preferredly in the low temperature range and in the high temperature
+# range, respectively. Of course not a very senseful approach but
+# a good demo to see the effect of weights in a fit.
+#
+
+# Column
+# 1 2 3 4 5
+
+39.471 1.03307 1.0 0.98765 0.010
+40.091 1.03246 1.0 0.98765 0.010
+40.602 1.03197 1.0 0.98765 0.010
+41.058 1.03153 1.0 0.98765 0.010
+41.438 1.03117 1.0 0.98765 0.010
+41.880 1.03074 1.0 0.98765 0.010
+42.437 1.03021 1.0 0.98765 0.010
+42.836 1.02982 1.0 0.98765 0.010
+43.209 1.02946 1.0 0.98765 0.010
+43.599 1.02907 1.0 0.98765 0.010
+43.997 1.02867 1.0 0.98765 0.010
+44.313 1.02833 1.0 0.98765 0.010
+44.908 1.02765 1.0 0.98765 0.010
+45.169 1.02735 1.0 0.98765 0.010
+45.594 1.02683 1.0 0.98765 0.010
+45.743 1.02661 999.0 0.98765 0.010
+45.796 1.02650 999.0 0.98765 0.010
+45.816 1.02644 999.0 0.98765 0.010
+45.841 1.02634 999.0 0.98765 0.010
+45.876 1.02623 999.0 0.98765 0.010
+45.908 1.02611 999.0 0.98765 0.010
+45.959 1.02592 999.0 0.98765 0.010
+46.008 1.02561 999.0 0.12345 0.001
+46.040 1.02526 999.0 0.12345 0.001
+46.060 1.02506 999.0 0.12345 0.001
+46.096 1.02500 999.0 0.12345 0.001
+46.126 1.02496 999.0 0.12345 0.001
+46.149 1.02494 999.0 0.12345 0.001
+46.372 1.02474 999.0 0.12345 0.001
+46.625 1.02452 999.0 0.12345 0.001
+46.945 1.02425 999.0 0.12345 0.001
+47.326 1.02393 999.0 0.12345 0.001
+47.708 1.02361 999.0 0.12345 0.001
+48.095 1.02329 999.0 0.12345 0.001
+48.540 1.02293 999.0 0.12345 0.001
+48.927 1.02262 999.0 0.12345 0.001
+49.314 1.02231 999.0 0.12345 0.001
+