# create the chart with 3 dimensions
cat <<EOF
-CHART ap_clients.${dev} '' "Connected clients to ${ssid} on ${dev}" "clients" ${dev} ap.clients line $[ap_priority + 1] $ap_update_every
+CHART ap_clients.${dev} '' "Connected clients to ${ssid} on ${dev}" "clients" ${dev} ap.clients line $((ap_priority + 1)) $ap_update_every
DIMENSION clients '' absolute 1 1
-CHART ap_bandwidth.${dev} '' "Bandwidth for ${ssid} on ${dev}" "kilobits/s" ${dev} ap.net area $[ap_priority + 2] $ap_update_every
+CHART ap_bandwidth.${dev} '' "Bandwidth for ${ssid} on ${dev}" "kilobits/s" ${dev} ap.net area $((ap_priority + 2)) $ap_update_every
DIMENSION received '' incremental 8 1024
DIMENSION sent '' incremental -8 1024
-CHART ap_packets.${dev} '' "Packets for ${ssid} on ${dev}" "packets/s" ${dev} ap.packets line $[ap_priority + 3] $ap_update_every
+CHART ap_packets.${dev} '' "Packets for ${ssid} on ${dev}" "packets/s" ${dev} ap.packets line $((ap_priority + 3)) $ap_update_every
DIMENSION received '' incremental 1 1
DIMENSION sent '' incremental -1 1
-CHART ap_issues.${dev} '' "Transmit Issues for ${ssid} on ${dev}" "issues/s" ${dev} ap.issues line $[ap_priority + 4] $ap_update_every
+CHART ap_issues.${dev} '' "Transmit Issues for ${ssid} on ${dev}" "issues/s" ${dev} ap.issues line $((ap_priority + 4)) $ap_update_every
DIMENSION retries 'tx retries' incremental 1 1
DIMENSION failures 'tx failures' incremental -1 1
-CHART ap_signal.${dev} '' "Average Signal for ${ssid} on ${dev}" "dBm" ${dev} ap.signal line $[ap_priority + 5] $ap_update_every
+CHART ap_signal.${dev} '' "Average Signal for ${ssid} on ${dev}" "dBm" ${dev} ap.signal line $((ap_priority + 5)) $ap_update_every
DIMENSION signal 'average signal' absolute 1 1
-CHART ap_bitrate.${dev} '' "Bitrate for ${ssid} on ${dev}" "Mbps" ${dev} ap.bitrate line $[ap_priority + 6] $ap_update_every
+CHART ap_bitrate.${dev} '' "Bitrate for ${ssid} on ${dev}" "Mbps" ${dev} ap.bitrate line $((ap_priority + 6)) $ap_update_every
DIMENSION receive '' absolute 1 1000
DIMENSION transmit '' absolute -1 1000
DIMENSION expected 'expected throughput' absolute 1 1000