Does anyone know an easy way to make a double interpolation?
As a example interpolate the data below for a temp of 45 and a pressure of 5 which should return 5
<TABLE style="WIDTH: 192pt; BORDER-COLLAPSE: collapse" border=0 cellSpacing=0 cellPadding=0 width=256><COLGROUP><COL style="WIDTH: 48pt" span=4 width=64><TBODY><TR style="HEIGHT: 29.25pt; mso-height-source: userset" height=39><TD style="BORDER-BOTTOM: #f0f0f0; BORDER-LEFT: #f0f0f0; BACKGROUND-COLOR: transparent; WIDTH: 48pt; HEIGHT: 29.25pt; BORDER-TOP: #f0f0f0; BORDER-RIGHT: #f0f0f0" id=td_post_2592142 height=39 width=64></TD><TD style="BORDER-BOTTOM: #cccccc 1pt solid; BORDER-LEFT: #cccccc 1pt solid; BACKGROUND-COLOR: #ffffcc; WIDTH: 144pt; BORDER-TOP: #cccccc 1pt solid; BORDER-RIGHT: #cccccc 1pt solid" class=xl68 width=192 colSpan=3>pressures</TD></TR><TR style="HEIGHT: 15.75pt" height=21><TD style="BORDER-BOTTOM: #cccccc 1pt solid; BORDER-LEFT: silver 1.5pt solid; BACKGROUND-COLOR: #99ffcc; WIDTH: 48pt; HEIGHT: 15.75pt; BORDER-TOP: #cccccc 1pt solid; BORDER-RIGHT: #cccccc 1pt solid" class=xl67 height=21 width=64>temp</TD><TD style="BORDER-BOTTOM: #cccccc 1pt solid; BORDER-LEFT: #cccccc; BACKGROUND-COLOR: #ffffcc; WIDTH: 48pt; BORDER-TOP: #cccccc; BORDER-RIGHT: #cccccc 1pt solid" class=xl65 width=64>0</TD><TD style="BORDER-BOTTOM: #cccccc 1pt solid; BORDER-LEFT: #cccccc; BACKGROUND-COLOR: #ffffcc; WIDTH: 48pt; BORDER-TOP: #cccccc; BORDER-RIGHT: #cccccc 1pt solid" class=xl65 width=64>10</TD><TD style="BORDER-BOTTOM: #cccccc 1pt solid; BORDER-LEFT: #cccccc; BACKGROUND-COLOR: #ffffcc; WIDTH: 48pt; BORDER-TOP: #cccccc; BORDER-RIGHT: #cccccc 1pt solid" class=xl65 width=64>20</TD></TR><TR style="HEIGHT: 15.75pt" height=21><TD style="BORDER-BOTTOM: #cccccc 1pt solid; BORDER-LEFT: silver 1.5pt solid; BACKGROUND-COLOR: #99ffcc; WIDTH: 48pt; HEIGHT: 15.75pt; BORDER-TOP: #cccccc; BORDER-RIGHT: #cccccc 1pt solid" class=xl67 height=21 width=64>30</TD><TD style="BORDER-BOTTOM: #cccccc 1pt solid; BORDER-LEFT: #cccccc; BACKGROUND-COLOR: transparent; WIDTH: 48pt; BORDER-TOP: #cccccc; BORDER-RIGHT: #cccccc 1pt solid" class=xl66 width=64>1</TD><TD style="BORDER-BOTTOM: #cccccc 1pt solid; BORDER-LEFT: #cccccc; BACKGROUND-COLOR: transparent; WIDTH: 48pt; BORDER-TOP: #cccccc; BORDER-RIGHT: #cccccc 1pt solid" class=xl66 width=64>6</TD><TD style="BORDER-BOTTOM: #cccccc 1pt solid; BORDER-LEFT: #cccccc; BACKGROUND-COLOR: transparent; WIDTH: 48pt; BORDER-TOP: #cccccc; BORDER-RIGHT: #cccccc 1pt solid" class=xl66 width=64>11</TD></TR><TR style="HEIGHT: 15.75pt" height=21><TD style="BORDER-BOTTOM: #cccccc 1pt solid; BORDER-LEFT: silver 1.5pt solid; BACKGROUND-COLOR: #99ffcc; WIDTH: 48pt; HEIGHT: 15.75pt; BORDER-TOP: #cccccc; BORDER-RIGHT: #cccccc 1pt solid" class=xl67 height=21 width=64>40</TD><TD style="BORDER-BOTTOM: #cccccc 1pt solid; BORDER-LEFT: #cccccc; BACKGROUND-COLOR: transparent; WIDTH: 48pt; BORDER-TOP: #cccccc; BORDER-RIGHT: #cccccc 1pt solid" class=xl66 width=64>2</TD><TD style="BORDER-BOTTOM: #cccccc 1pt solid; BORDER-LEFT: #cccccc; BACKGROUND-COLOR: transparent; WIDTH: 48pt; BORDER-TOP: #cccccc; BORDER-RIGHT: #cccccc 1pt solid" class=xl66 width=64>7</TD><TD style="BORDER-BOTTOM: #cccccc 1pt solid; BORDER-LEFT: #cccccc; BACKGROUND-COLOR: transparent; WIDTH: 48pt; BORDER-TOP: #cccccc; BORDER-RIGHT: #cccccc 1pt solid" class=xl66 width=64>12</TD></TR><TR style="HEIGHT: 15.75pt" height=21><TD style="BORDER-BOTTOM: #cccccc 1pt solid; BORDER-LEFT: silver 1.5pt solid; BACKGROUND-COLOR: #99ffcc; WIDTH: 48pt; HEIGHT: 15.75pt; BORDER-TOP: #cccccc; BORDER-RIGHT: #cccccc 1pt solid" class=xl67 height=21 width=64>50</TD><TD style="BORDER-BOTTOM: #cccccc 1pt solid; BORDER-LEFT: #cccccc; BACKGROUND-COLOR: transparent; WIDTH: 48pt; BORDER-TOP: #cccccc; BORDER-RIGHT: #cccccc 1pt solid" class=xl66 width=64>3</TD><TD style="BORDER-BOTTOM: #cccccc 1pt solid; BORDER-LEFT: #cccccc; BACKGROUND-COLOR: transparent; WIDTH: 48pt; BORDER-TOP: #cccccc; BORDER-RIGHT: #cccccc 1pt solid" class=xl66 width=64>8</TD><TD style="BORDER-BOTTOM: #cccccc 1pt solid; BORDER-LEFT: #cccccc; BACKGROUND-COLOR: transparent; WIDTH: 48pt; BORDER-TOP: #cccccc; BORDER-RIGHT: #cccccc 1pt solid" class=xl66 width=64>13</TD></TR><TR style="HEIGHT: 15.75pt" height=21><TD style="BORDER-BOTTOM: #cccccc 1pt solid; BORDER-LEFT: silver 1.5pt solid; BACKGROUND-COLOR: #99ffcc; WIDTH: 48pt; HEIGHT: 15.75pt; BORDER-TOP: #cccccc; BORDER-RIGHT: #cccccc 1pt solid" class=xl67 height=21 width=64>60</TD><TD style="BORDER-BOTTOM: #cccccc 1pt solid; BORDER-LEFT: #cccccc; BACKGROUND-COLOR: transparent; WIDTH: 48pt; BORDER-TOP: #cccccc; BORDER-RIGHT: #cccccc 1pt solid" class=xl66 width=64>4</TD><TD style="BORDER-BOTTOM: #cccccc 1pt solid; BORDER-LEFT: #cccccc; BACKGROUND-COLOR: transparent; WIDTH: 48pt; BORDER-TOP: #cccccc; BORDER-RIGHT: #cccccc 1pt solid" class=xl66 width=64>9</TD><TD style="BORDER-BOTTOM: #cccccc 1pt solid; BORDER-LEFT: #cccccc; BACKGROUND-COLOR: transparent; WIDTH: 48pt; BORDER-TOP: #cccccc; BORDER-RIGHT: #cccccc 1pt solid" class=xl66 width=64>14</TD></TR><TR style="HEIGHT: 15.75pt" height=21><TD style="BORDER-BOTTOM: #cccccc 1pt solid; BORDER-LEFT: silver 1.5pt solid; BACKGROUND-COLOR: #99ffcc; WIDTH: 48pt; HEIGHT: 15.75pt; BORDER-TOP: #cccccc; BORDER-RIGHT: #cccccc 1pt solid" class=xl67 height=21 width=64>70</TD><TD style="BORDER-BOTTOM: #cccccc 1pt solid; BORDER-LEFT: #cccccc; BACKGROUND-COLOR: transparent; WIDTH: 48pt; BORDER-TOP: #cccccc; BORDER-RIGHT: #cccccc 1pt solid" class=xl66 width=64>5</TD><TD style="BORDER-BOTTOM: #cccccc 1pt solid; BORDER-LEFT: #cccccc; BACKGROUND-COLOR: transparent; WIDTH: 48pt; BORDER-TOP: #cccccc; BORDER-RIGHT: #cccccc 1pt solid" class=xl66 width=64>10</TD><TD style="BORDER-BOTTOM: #cccccc 1pt solid; BORDER-LEFT: #cccccc; BACKGROUND-COLOR: transparent; WIDTH: 48pt; BORDER-TOP: #cccccc; BORDER-RIGHT: #cccccc 1pt solid" class=xl66 width=64>15</TD></TR></TBODY></TABLE>
As a example interpolate the data below for a temp of 45 and a pressure of 5 which should return 5
<TABLE style="WIDTH: 192pt; BORDER-COLLAPSE: collapse" border=0 cellSpacing=0 cellPadding=0 width=256><COLGROUP><COL style="WIDTH: 48pt" span=4 width=64><TBODY><TR style="HEIGHT: 29.25pt; mso-height-source: userset" height=39><TD style="BORDER-BOTTOM: #f0f0f0; BORDER-LEFT: #f0f0f0; BACKGROUND-COLOR: transparent; WIDTH: 48pt; HEIGHT: 29.25pt; BORDER-TOP: #f0f0f0; BORDER-RIGHT: #f0f0f0" id=td_post_2592142 height=39 width=64></TD><TD style="BORDER-BOTTOM: #cccccc 1pt solid; BORDER-LEFT: #cccccc 1pt solid; BACKGROUND-COLOR: #ffffcc; WIDTH: 144pt; BORDER-TOP: #cccccc 1pt solid; BORDER-RIGHT: #cccccc 1pt solid" class=xl68 width=192 colSpan=3>pressures</TD></TR><TR style="HEIGHT: 15.75pt" height=21><TD style="BORDER-BOTTOM: #cccccc 1pt solid; BORDER-LEFT: silver 1.5pt solid; BACKGROUND-COLOR: #99ffcc; WIDTH: 48pt; HEIGHT: 15.75pt; BORDER-TOP: #cccccc 1pt solid; BORDER-RIGHT: #cccccc 1pt solid" class=xl67 height=21 width=64>temp</TD><TD style="BORDER-BOTTOM: #cccccc 1pt solid; BORDER-LEFT: #cccccc; BACKGROUND-COLOR: #ffffcc; WIDTH: 48pt; BORDER-TOP: #cccccc; BORDER-RIGHT: #cccccc 1pt solid" class=xl65 width=64>0</TD><TD style="BORDER-BOTTOM: #cccccc 1pt solid; BORDER-LEFT: #cccccc; BACKGROUND-COLOR: #ffffcc; WIDTH: 48pt; BORDER-TOP: #cccccc; BORDER-RIGHT: #cccccc 1pt solid" class=xl65 width=64>10</TD><TD style="BORDER-BOTTOM: #cccccc 1pt solid; BORDER-LEFT: #cccccc; BACKGROUND-COLOR: #ffffcc; WIDTH: 48pt; BORDER-TOP: #cccccc; BORDER-RIGHT: #cccccc 1pt solid" class=xl65 width=64>20</TD></TR><TR style="HEIGHT: 15.75pt" height=21><TD style="BORDER-BOTTOM: #cccccc 1pt solid; BORDER-LEFT: silver 1.5pt solid; BACKGROUND-COLOR: #99ffcc; WIDTH: 48pt; HEIGHT: 15.75pt; BORDER-TOP: #cccccc; BORDER-RIGHT: #cccccc 1pt solid" class=xl67 height=21 width=64>30</TD><TD style="BORDER-BOTTOM: #cccccc 1pt solid; BORDER-LEFT: #cccccc; BACKGROUND-COLOR: transparent; WIDTH: 48pt; BORDER-TOP: #cccccc; BORDER-RIGHT: #cccccc 1pt solid" class=xl66 width=64>1</TD><TD style="BORDER-BOTTOM: #cccccc 1pt solid; BORDER-LEFT: #cccccc; BACKGROUND-COLOR: transparent; WIDTH: 48pt; BORDER-TOP: #cccccc; BORDER-RIGHT: #cccccc 1pt solid" class=xl66 width=64>6</TD><TD style="BORDER-BOTTOM: #cccccc 1pt solid; BORDER-LEFT: #cccccc; BACKGROUND-COLOR: transparent; WIDTH: 48pt; BORDER-TOP: #cccccc; BORDER-RIGHT: #cccccc 1pt solid" class=xl66 width=64>11</TD></TR><TR style="HEIGHT: 15.75pt" height=21><TD style="BORDER-BOTTOM: #cccccc 1pt solid; BORDER-LEFT: silver 1.5pt solid; BACKGROUND-COLOR: #99ffcc; WIDTH: 48pt; HEIGHT: 15.75pt; BORDER-TOP: #cccccc; BORDER-RIGHT: #cccccc 1pt solid" class=xl67 height=21 width=64>40</TD><TD style="BORDER-BOTTOM: #cccccc 1pt solid; BORDER-LEFT: #cccccc; BACKGROUND-COLOR: transparent; WIDTH: 48pt; BORDER-TOP: #cccccc; BORDER-RIGHT: #cccccc 1pt solid" class=xl66 width=64>2</TD><TD style="BORDER-BOTTOM: #cccccc 1pt solid; BORDER-LEFT: #cccccc; BACKGROUND-COLOR: transparent; WIDTH: 48pt; BORDER-TOP: #cccccc; BORDER-RIGHT: #cccccc 1pt solid" class=xl66 width=64>7</TD><TD style="BORDER-BOTTOM: #cccccc 1pt solid; BORDER-LEFT: #cccccc; BACKGROUND-COLOR: transparent; WIDTH: 48pt; BORDER-TOP: #cccccc; BORDER-RIGHT: #cccccc 1pt solid" class=xl66 width=64>12</TD></TR><TR style="HEIGHT: 15.75pt" height=21><TD style="BORDER-BOTTOM: #cccccc 1pt solid; BORDER-LEFT: silver 1.5pt solid; BACKGROUND-COLOR: #99ffcc; WIDTH: 48pt; HEIGHT: 15.75pt; BORDER-TOP: #cccccc; BORDER-RIGHT: #cccccc 1pt solid" class=xl67 height=21 width=64>50</TD><TD style="BORDER-BOTTOM: #cccccc 1pt solid; BORDER-LEFT: #cccccc; BACKGROUND-COLOR: transparent; WIDTH: 48pt; BORDER-TOP: #cccccc; BORDER-RIGHT: #cccccc 1pt solid" class=xl66 width=64>3</TD><TD style="BORDER-BOTTOM: #cccccc 1pt solid; BORDER-LEFT: #cccccc; BACKGROUND-COLOR: transparent; WIDTH: 48pt; BORDER-TOP: #cccccc; BORDER-RIGHT: #cccccc 1pt solid" class=xl66 width=64>8</TD><TD style="BORDER-BOTTOM: #cccccc 1pt solid; BORDER-LEFT: #cccccc; BACKGROUND-COLOR: transparent; WIDTH: 48pt; BORDER-TOP: #cccccc; BORDER-RIGHT: #cccccc 1pt solid" class=xl66 width=64>13</TD></TR><TR style="HEIGHT: 15.75pt" height=21><TD style="BORDER-BOTTOM: #cccccc 1pt solid; BORDER-LEFT: silver 1.5pt solid; BACKGROUND-COLOR: #99ffcc; WIDTH: 48pt; HEIGHT: 15.75pt; BORDER-TOP: #cccccc; BORDER-RIGHT: #cccccc 1pt solid" class=xl67 height=21 width=64>60</TD><TD style="BORDER-BOTTOM: #cccccc 1pt solid; BORDER-LEFT: #cccccc; BACKGROUND-COLOR: transparent; WIDTH: 48pt; BORDER-TOP: #cccccc; BORDER-RIGHT: #cccccc 1pt solid" class=xl66 width=64>4</TD><TD style="BORDER-BOTTOM: #cccccc 1pt solid; BORDER-LEFT: #cccccc; BACKGROUND-COLOR: transparent; WIDTH: 48pt; BORDER-TOP: #cccccc; BORDER-RIGHT: #cccccc 1pt solid" class=xl66 width=64>9</TD><TD style="BORDER-BOTTOM: #cccccc 1pt solid; BORDER-LEFT: #cccccc; BACKGROUND-COLOR: transparent; WIDTH: 48pt; BORDER-TOP: #cccccc; BORDER-RIGHT: #cccccc 1pt solid" class=xl66 width=64>14</TD></TR><TR style="HEIGHT: 15.75pt" height=21><TD style="BORDER-BOTTOM: #cccccc 1pt solid; BORDER-LEFT: silver 1.5pt solid; BACKGROUND-COLOR: #99ffcc; WIDTH: 48pt; HEIGHT: 15.75pt; BORDER-TOP: #cccccc; BORDER-RIGHT: #cccccc 1pt solid" class=xl67 height=21 width=64>70</TD><TD style="BORDER-BOTTOM: #cccccc 1pt solid; BORDER-LEFT: #cccccc; BACKGROUND-COLOR: transparent; WIDTH: 48pt; BORDER-TOP: #cccccc; BORDER-RIGHT: #cccccc 1pt solid" class=xl66 width=64>5</TD><TD style="BORDER-BOTTOM: #cccccc 1pt solid; BORDER-LEFT: #cccccc; BACKGROUND-COLOR: transparent; WIDTH: 48pt; BORDER-TOP: #cccccc; BORDER-RIGHT: #cccccc 1pt solid" class=xl66 width=64>10</TD><TD style="BORDER-BOTTOM: #cccccc 1pt solid; BORDER-LEFT: #cccccc; BACKGROUND-COLOR: transparent; WIDTH: 48pt; BORDER-TOP: #cccccc; BORDER-RIGHT: #cccccc 1pt solid" class=xl66 width=64>15</TD></TR></TBODY></TABLE>